Muslim conquest of Persia

Muslim conquest of Persia
Part of the Muslim conquests
Mounted Persian knight, Taq-e Bostan, Iran.
Date 633-644 Location Mesopotamia, Caucasus, Persia, and Bactria Result Rashidun victory Territorial changes Mesopotamia and the Sassanid Empire annexed by Muslims
Belligerents
Sassanid Empire, Arab Christians Byzantine Empire	Rashidun Caliphate
Commanders and leaders
Emperor Yazdegerd III † Rostam Farrokhzād † Mahbuzan Huzail ibn Imran Hormuz † Anushjan Andarzaghar † Bahman Pirouzan † Jaban † Mihran † Hormuzan Mardan Shah † Bahram Isandir Karinz ibn Karianz Wahman Mardanshah Jalinus† Beerzan†	Caliph Abu Bakr Khalid ibn Walid Muthana ibn Haris † Caliph Umar Abu Ubaid † Saad ibn Abi Waqqas Zuhra ibn Al-Hawiyya † Hashim ibn Uthba Qa’qa ibn Amr Abu Musa Ashaari Ammar ibn Yasir Nouman ibn Muqarrin † Hudheifa ibn Al Yaman Mugheera ibn Shuba Usman ibn Abi al-Aas Asim ibn Amr Ahnaf ibn Qais Abdullah ibn Aamir

The Muslim conquest of Persia led to the end of the Sassanid Empire in 644, of the Sassanid dynasty in 651 and the eventual extirpation of the Zoroastrian religion in Persia. The Sassanian Empire was first invaded by the Muslims in present day Iraq in 633 under general Khalid ibn Walid, which resulted in the Muslim conquest of Iraq. Following the transfer of Khalid to the Roman front in the Levant, the Muslims eventually lost Iraq to Persian counterattacks. The second invasion of Iraq began in 636 under Saad ibn Abi Waqqas when after a key victory at the Battle of Qadisiyyah Sassanid control west of Persia was permanently ended. The Zagros mountains became a natural barrier and border between the Rashidun Caliphate and the Sassanid empire. Owing to continuous raids by Persians in Iraq, Caliph Umar ordered a wholesale invasion of the Sassanid Persian empire in 642 which came to an end with the complete conquest of the Sassanids empire by mid 644. The quick conquest of Persia in a series of well coordinated multi-pronged attacks, operated by Caliph Umar from Madinah several thousand miles from the battlefields in Persia, became his greatest triumph, marking his reputation among the greatest strategists and political geniuses of history. Most Muslim historians have long offered the idea that Persia, on the verge of the Arab invasion, was a society in decline and decay and that it consequently embraced the invading Arab armies with open arms. However some other authors have for example used exclusively Arab sources to illustrate that "contrary to the claims of Muslim apologists, Iranians in fact fought long and hard against the invading Arabs." This view furthermore holds that, once politically conquered, the Persians began to resist the Arabs culturally and succeeded in forcing their own ways on the Arabs.

Persia Before the Conquest

Since the 1st century BC, the border between the Roman (later Byzantine) and Parthian (later Sassanid) empires had been the Euphrates river. The border was constantly contested. Most battles, and thus most fortifications, were concentrated in the hilly regions of the north, as the vast Arabian or Syrian Desert (Roman Arabia) separated the rival empires in the south. The only dangers expected from the south were occasional raids by nomadic Arab tribesmen. Both empires therefore allied themselves with small, semi-independent Arab principalities, which served as buffer states and protected Byzantium and Persia from Bedouin attacks. The Byzantine clients were the Ghassanids; the Persian clients were the Lakhmids. The Ghassanids and Lakhmids feuded constantly — which kept them occupied, but that did not greatly affect the Byzantines or the Persians. In the 6th and 7th centuries, various factors destroyed the balance of power that had held for so many centuries.

Revolt of the Arab Client States (602)

Ancient Iranians attached great importance to music and poetry, as they still do today. This 7th century plate depicts Sassanid era musicians.

The Byzantine clients, the Arab Ghassanids, converted to the Monophysite form of Christianity, which was regarded as heretical by the established Byzantine Orthodox Church. The Byzantines attempted to suppress the heresy, alienating the Ghassanids and sparking rebellions on their desert frontiers. The Lakhmids also revolted against the Persian king Khusrau II. Nu'man III (son of Al-Monder IV), the first Christian Lakhmid king, was deposed and killed by Khusrau II in 602, because of his attempt to throw off the Persian tutelage. After Khusrau's assassination, the Persian Empire fractured and the Lakhmids were effectively semi-independent. It is now widely believed that annexation of Lakhmid kingdom was one of the main factors behind the Fall of Sassanid dynasty to the Muslim Arabs and the Islamic conquest of Persia, as the Lakhmids agreed to act as spies for the Muslims after being defeated in the Battle of Hira by Khalid ibn al-Walid.

Byzantine–Sassanid War (612 - 629)

Main article: Byzantine–Sassanid Wars

See also: Fall of Sassanid dynasty

The Persian ruler Khosrau II (Parviz) defeated a dangerous rebellion within his own empire (the Bahram Chobin's rebellion). He afterwards turned his energies outwards, upon the traditional Byzantine enemies in the Roman-Persian Wars. For a few years, he succeeded gloriously. From 612 to 622, he extended the Persian borders almost to the same extent that they were under the Achaemenid dynasty (550–330 BC), capturing the cities Antioch, Damascus, Alexandria, and Jerusalem.

The Byzantines regrouped and pushed back in 622 under Heraclius. Khosrau was defeated at the Battle of Nineveh in 627, and the Byzantines recaptured all of Syria and penetrated far into the Persian provinces of Mesopotamia. In 629, Khosrau's son agreed to peace, and the border between the two empires was once again the same as it was in 602.

Assassination of Khosrau II

Sassanid King Khosrau II submitting to the Byzantine Emperor Heraclius, from a plaque on a 12th century French cross.

Khosrau II was assassinated in 628 and as a result, there were numerous claimants to the throne; from 628 to 632 there were ten kings and queens of Persia. The last, Yazdegerd III, was a grandson of Khosrau II and was said to be a mere child. However, no date of birth is known.

During Prophet Muhammad's Life

After the Treaty of Hudaybiyyah in 628, Muhammad sent many letters to the princes, kings and chiefs of the various tribes and kingdoms of the time inviting them to convert to Islam. These letters were carried by ambassadors to Iran, Byzantium, Ethiopia, Egypt, Yemen, and Hira (Iraq) on the same day. This assertion has been cast into scrutiny by some modern historians of Islam—notably Grimme and Caetani. Particularly in dispute is the assertion that Khosrau II received a letter from Muhammad, as the Sassanid court ceremony was notoriously intricate, and it is unlikely that a letter from what at the time was a minor regional power would have reached the hands of the Shahanshah.

With regards to Iran, Muslim histories further recount that at the beginning of the seventh year of migration, Muhammad appointed one of his officers, Abdullah Huzafah Sahmi Qarashi, to carry his letter to Khosrau II inviting him to Islam:

"In the name of God, the Beneficent, the Merciful. From Muhammad, the Messenger of God, to the great Kisra of Iran. Peace be upon him, who seeks truth and expresses belief in God and in His Prophet and testifies that there is no god but God and that He has no partner, and who believes that Muhammad is His servant and Prophet. Under the Command of God, I invite you to Him. He has sent me for the guidance of all people so that I may warn them all of His wrath and may present the unbelievers with an ultimatum. Embrace Islam so that you may remain safe. And if you refuse to accept Islam, you will be responsible for the sins of the Magi."

There are differing accounts of the reaction of Khosrau II. Nearly all assert that he destroyed the letter in anger; the variations concentrate on the extent and detail of his response.

Rise of the Caliphate

Mohammad died in June 632, and Abu Bakr was appointed Caliph and political successor at Medina. Soon after Abu Bakr's succession, several Arab tribes revolted against in the Ridda wars (Arabic for the Wars of Apostasy). The Campaign of the Apostasy was fought and completed during the eleventh year of the Hijri. The year 12 Hijri dawned, on 18 March 633, with Arabia united under the central authority of the Caliph at Medina. Whether Abu Bakr intended a full-out imperial conquest or not is hard to say; he did, however, set in motion a historical trajectory that in just a few short decades would lead to one of the largest empires in history, the Caliphate, beginning with a confrontation with the Sassanid Empire under the general Khalid ibn al-Walid.

First conquest of Mesopotamia (633)

Map detailing the route of Khalid ibn Walid's conquest of Iraq.

After the Ridda Wars, a tribal chief of north eastern Arabia, Misnah ibn Haris, raided the Persian towns in Iraq. With the success of the raids, a considerable amount of booty was collected. Misnah ibn Haris went to Medina to inform Caliph Abu Bakr about his success and was appointed commander of his people, after which he began to raid deeper into Iraq. Using the mobility of his light cavalry he could easily raid any town near the desert and disappear again into the desert, into which the Sassanid army was unable to chase them. Misnah’s acts made Abu Bakr think about the expansion of the Rashidun Empire.

Abu Bakr started with the invasion of Iraq. The problems faced by Abu Bakr were that the Arabs feared the Persians with a deep, unreasoning fear which ran in the tribal consciousness as a racial complex and was the result of centuries of Persian power and glory. In return, the Persians regarded the Arabs with contempt. It was important not to suffer a defeat, for that would confirm and strengthen this instinctive fear. To be certain of victory, Abu Bakr made two decisions concerning the attack on Persia: first, the invading army would consist entirely of volunteers; and second, to put in command of the army his best general: Khalid ibn al-Walid. After defeating the self-proclaimed prophet Musaylimah in the Battle of Yamama, Khalid was still at Al-Yamama when Abu Bakr sent him orders to invade the Sassanid Empire. Making Al-Hirah the objective of Khalid, Abu Bakr sent reinforcements and ordered the tribal chiefs of north eastern Arabia, Misnah ibn Haris, Mazhur bin Adi, Harmala and Sulma to operate under the command of Khalid along with their men. Around the third week of March 633 (first week of Muharram 12th Hijrah) Khalid set out from Al-Yamama with an army of 10,000. The tribal chiefs, with 2,000 warriors each, joined Khalid; so Khalid entered the Persian Empire with 18,000 troops.

After entering Iraq with his army of 18,000, Khalid won decisive victories in four consecutive battles: the Battle of Chains, fought in April 633 A.D; the Battle of River, fought in the 3rd week of April 633 A.D; the Battle of Walaja, fought in May 633 A.D (where he successfully used a double envelopment manoeuvre), and the Battle of Ullais, fought in the mid of May, 633 A.D. By now the Persian court, already disturbed by internal problems, was down and out. In the last week of May 633 A.D, Hira, the capital city of Iraq fell to the Muslims after their victory in the Siege of Hira. After resting his armies, in June 633 A.D Khalid laid siege to the city of Al Anbar, which resisted and eventually surrendered after a siege of a few weeks in July 633 A.D after the Siege of Al-Anbar. Khalid then moved towards the south, and conquered the city of Ein ul Tamr after the Battle of Ein ut Tamr in the last week of July, 633 A.D. By now, almost the whole of Iraq (Euphrates region) was under Islamic control. Khalid got a call of help from northern Arabia at Daumat-ul-Jandal, where another Muslim Arab general, Ayaz bin Ghanam, was trapped among the rebel tribes. Khalid went to Daumat-ul-jandal and defeated the rebels in the Battle of Daumat-ul-jandal in the last week of August, 633 A.D. Returning from Arabia, he got news of the assembling of a large Persian army. He decided to defeat them all separately to avoid the risk of being defeated by a large unified Persian army. Four divisions of Persian and Christian Arab auxiliaries were present at Hanafiz, Zumiel, Sanni and Muzieh. Khalid devised a brilliant plan to destroy the Persian forces. He divided his army in three units, and attacked the Persian forces in well coordinated attacks from three different sides at night, starting from the Battle of Muzieh, then the Battle of Sanni, and finally the Battle of Zumail during November 633 A.D. These devastating defeats ended Persian control over Iraq, and left the Persian capital Ctesiphon unguarded and vulnerable to Muslim attack. Before attacking the Persian capital, Khalid decided to eliminate all Persian forces in the south and west. He accordingly marched against the border city of Firaz, where he defeated the combined forces of the Sassanid Persians, the Byzantine Romans and Christian Arabs in the Battle of Firaz in December 633 A.D. This was the last battle in his conquest of Iraq. While Khalid was on his way to attack Qadissiyah (a key fort in the way to the Persian capital Ctesiphon), he received a letter from Caliph Abu Bakr and was sent to the Roman front in Syria to assume the command of the Muslim armies to conquer Roman Syria.

Second invasion of Mesopotamia (636)

Main article: Battle of Qadisiyyah

According to the will of Abu Bakr, Umar was to continue the conquest of Syria and Iraq. On the north eastern borders of the Empire, in Iraq, the situation was deteriorating day by day. During Abu Bakr’s era, Khalid ibn al-Walid who had conquered Iraq, was sent to the Syrian front to command the Islamic armies there. As soon as Khalid had left Iraq with half his army of 9000 soldiers, the Persians decided to take back their lost territory. The Muslim army in Iraq was forced to leave the conquered areas and concentrate on the border areas. Umar immediately sent reinforcements to aid Misna ibn Haris in Iraq under the command of Abu Ubaid al Saqafi. The Persian forces defeated Abu Ubaid in the Battle of Bridge. However, later Persian forces were defeated by Misnah bin harisah in the Battle of Baiyoub. In 635 Yazdgerd III sought alliance with Emperor Heraclius of the Eastern Roman Empire. Heraclius married his daughter (according to traditions, his grand daughter) to Yazdegerd III, an old Roman tradition to show alliance. While Heraclius prepared for a major offense in the Levant, Yazdegerd, meanwhile, ordered the concentration of massive armies to pull back the Muslims from Iraq for good. The goal was well coordinated attacks by both emperors, Heraclius in the Levant and Yazdegerd in Iraq, to annihilate the power of their common enemy Caliph Umar. Fate, however, had decided otherwise.

Battle of Qadisiyyah

Main article: Battle of Qadisiyyah

The site of the Battle of Qadisiyyah, showing Muslim army (in red) and Sassanid army (in blue).

Umar ordered his army to retreat to the bordering areas of Iraq near the Arabian desert and started raising armies to for the Persian campaign. Iraq was to be conquered once again, from the beginning. Armies were concentrated near Madinah and owning to the critical situation Umar decided to command the army in person. The idea was discouraged by the members of Majlis al Shura at Madinah. The Muslims were engaged on both fronts and Umar's presence in Madinah was necessary, as it was the only way he could handle the critical situation. Umar appointed Saad ibn Abi Waqqas as commander for campaign in Iraq who left Madinah with his army in May 636 and camped at Qadisiyyah in June. While Heraclius launched his offense in May 636, Yazdegerd, probably owning to exhausted conditions of his government, could not coordinate with Heraclius in that offense and a would be decisive plan missed the mark. Umar, having alleged intelligence of this alliance, devised his own plan. As battle was imminent with the Byzantines in Syria, Umar did not want to risk a decisive battle with two great powers simultaneously; in the case of defeat on either front the Muslim empire (which had already employed all of its available man power), could be paralyzed for this crucial moment of history. He wanted to finish with the Byzantines first, and thus reinforced the Muslim army at Yarmouk, sending 6000 soldiers as a reinforcement in small bands. This was done to give the impression of a continuous stream of reinforcement. Meanwhile, Umar engaged Yazdegerd III using deception tactics, ordering Saad to enter into peace negotiations with Yazdegerd III and invite him to Islam. Heraclius had instructed his general Vahan not to engage in battle with the Muslims until he received the orders. However, fearing more reinforcement for Muslims from Madinah, the Byzantines were left with no choice but to attack the Muslim forces before they became stronger. Heraclius's imperial army was annihilated at the Battle of Yarmouk in August 636 (three months before Qadisiyyah), ending the power of the Roman Emperor for good. Nevertheless, Yazdegerd III continued to execute his offensive plan and concentrated armies near his capital Ctesiphon.. With situations at ease at Syrian front, on Umar's instruction negotiations were halted as an open signal to Persians for battle. Saad defeated the powerful Persian army in the Battle of al-Qādisiyyah fought in 636 A.D the battle proved to be a key to Iraq. It marked the end of Sassanid rule west of Persia proper. The battle is regarded as one of the most decisive battle of Islamic and world history. The battle also achieved the death of the famed Persian general Rostam Farrokhzād. Saad later conquered Babylon, Koosie, Bahrahsher and Madein, and the capital city of Sassanid Empire Ctesiphon fell in March 637 after a siege of three months.

Conquest of Mesopotamia (636 - 638)

File:Ctesiphon, Iraq (2117465493).jpg

Remains of Taq-i Kisra, palace of the Sassanid Kings, Ctesiphon, Iraq.

After the conquest of Ctesiphon, several detachments were immediately sent west to capture Qarqeesia and Heet the forts at the border of the Byzantine Empire. Several fortified Persian armies were still active north-east of Ctesiphon at Jalula and north of the Tigris at Tikrit and Mosul. After withdrawal from Ctesiphon, the Persian armies gathered at Jalaula north-east of Ctesiphon. Jalaula was a place of strategic importance because from here routes led to Iraq, Khurasan and Azerbaijan. The Persian forces at Jalula were commanded by General Mihran. His deputy was General Khurrazad, a brother of General Rustam, who had commanded the Persian forces at the Battle of al-Qadisiyyah. As instructed by the Caliph Umar, Saad reported everything to Umar. The Caliph decided to deal with Jalula first. His plan was first to clear the way to the north before taking any decisive action against Tikrit and Mosul. Umar appointed Hashim ibn Uthba to the expedition of Jalula and Abdullah ibn Mutaam to conquer Tikrit and Mosul. In April 637, Hashim led 12,000 troops from Ctesiphon to win a victory over the Persians at the Battle of Jalula. He then laid siege to Jalula for seven months. After seizing a victory at Jalula, Abdullah ibn Mutaam marched against Tikrit and captured the city after fierce resistance and with the help of Christian Arabs. He next sent an army to Mosul which surrendered on the terms of Jizya. With victory at Jalula and occupation of the Tikrit-Mosul region, Muslim rule in Iraq was established.

After the conquest of Jalula, a Muslim force under Qa'qa marched in pursuit of the Persians. The Persian army that escaped from Jalaula took its position at Khaniqeen fifteen miles from Jalula on the road to Iran, under the command of General Mihran. Qa’qa defeated the Persian forces in the Battle of Khaniqeen and captured the city of Khaniqeen. The Persians withdrew to Hulwan. Qaqa moved to Hulwan and laid siege to the city which was captured in January 638. Qa’qa sought permission for operating deeper into Persian land, i.e. main land Iran, but Caliph Umar didn’t approve the proposal and wrote a historic letter to Saad saying:

"I wish that between the Suwad and the Persian hills there were walls which would prevent them from getting to us, and prevent us from getting to them. The fertile Suwad is sufficient for us; and I prefer the safety of the Muslims to the spoils of war."

Raids of Persians in Mesopotamia (638 - 641)

Winged sphinx from the palace of Darius the Great at Susa, captured by Rashidun general Abu Musa in 641.

By February 638 there was a lull in fighting on the Persian front. The Suwad, the Tigris valley, and the Euphrates valley were now under the complete control of the Muslims. The Persians had withdrawn to Persia proper, east of Zagros mountains. Persians kept on raiding Iraq, which remained politically unstable. Nevertheless it appeared as if this was going to be the dividing line between the Rashidun Caliphate and the Sassanids. In later part of the year 638 Hormuzan, who commanded one of the Persian corps at the Battle of Qadisiyyah and was one of the seven great chiefs of Persia, intensified his raids in Iraq, Saad according to Umar’s instructions took offensive against Hormuzan and Utbah ibn Ghazwan aided by Nouman ibn Muqarin attacked Ahwaz and forced Hormuzan to enter into a peace treaty with the Muslims according to which Ahwaz will remain Hormuzan’s estate and he will rule it as a vassal of the Muslims and will pay tritube. Hormuzan broke the treaty and revolted against the Muslims, Umar sent Abu Musa Ashaari, governor of Busra to deal with Hormuzan. Hormuzan was defeated and sought once again for peace, Umar accepted the offer and Hormuzan was again made vassal of the Muslims. This peace also proved short termed and once Hormuzan was reinforced by the fresh Persian troops sent by Emperor Yazdgerd III in late 640. The troops concentrated at Tuster north of Ahwaz, Umar sent Governor of Kufa, Ammar ibn Yasir, governor of Busra Abu Musa, and Nouman ibn Muqarin towards Tustar where Hormuzan was defeated, captured and sent to Madinah to Caliph Umar, where he apparently converted to Islam. He remained a useful adviser of Umar through out the campaign of conquest of Persia. He is also considered to be master mind behind the assassination of Caliph Umar in 644. After victory at Tustar, Abu Musa marched against Susa, a place of military importance, in January 641, which was captured after a siege of couple of months. Next Abu Musa marched against Junde Sabur, the only place left of military importance in the Persian province of Khuzistan which surrender to the Muslims after the siege of few weeks.

Battle of Nihawand (641)

Main article: Battle of Nahavand

A Sassanid army helmet

After the conquest of Khuzistan, the Caliph Umar wanted peace. They wanted to leave rest of Persia to the Persians. Umar said:

"I wish there were a mountain of fire between us and the Persians, so that neither could they get to us, nor we to them."

But the Persians thought differently. The pride of the imperial Persians had been hurt by the conquest of their land by the Arabs. They could not acquiesce in the occupation of their lands by the Arabs.

After defeat of Persian forces at the Battle of Jalula in 637, Emperor Yazdgerd III went to Rayy and from there moved to Merv where he set up his capital. From Merv, he directed his chiefs to conduct continuous raids in Iraq to destabilize the Muslim rule. Within the next four years, Yazdgerd III felt powerful enough to challenge the Muslims once again for the throne of Iraq. The Emperor sent a call to his people to drive away the Muslims from their lands. In response to the call, hardened veterans and young volunteers from all parts of Persia marched in large numbers to join the imperial standard and marched to Nihawand for the last titanic struggle for the between the forces of Caliphate and Sassanid Persia. 60,000 fighters assembled, commanded by Mardan Shah.

Governor of Kufa, Ammar ibn Yasir, received intelligence of the Persian movements and concentration at Nihawand. He reported the matter to Umar. Although Umar had expressed a desire for Iraq to be his eastern most frontier, he felt compelled to act given the concentration of Persian army at Nihawand. He believed that so long as Persia proper remained under Sassanid rule, Persian forces would continue raiding Iraq with a view to one day re-capture the country. Hudheifa ibn Al Yaman was appointed commander of the forces of Kufa, and was ordered to march to Nihawand. Governor of Busra Abu Musa, was to march to Nihawand commanding his forces of Busra Nouman ibn Muqarrin marched from Ctesiphon to Nihawand while Umar decided to lead the army concentrated at Madinah in person and command the Muslims at the battle. Umar’s decision of commanding the army in person was not popularly accepted by the members of Majlis al Shura at Madinah. It was suggested that Umar should command the campaign from Madinah, and should appoint an astute military commander to lead the Muslims at Nihawand. Umar appointed Mugheera ibn Shuba, commander of the forces concentrated at Madinah and appointed Nouman ibn Muqarrin as commander in chief of the Muslims at Nihawand. The Muslim army left for Nihawand and first concentrated at Tazar, and then moved to Nihawand and defeated the Persian forces at the Battle of Nihawand in December 641. Nouman died in action, and as per Umar’s instructions Hudheifa ibn Al Yaman became new commander in chief. After the victory at Nihawand, the Muslim army captured the whole district of Hamadan after feeble resistance by Persians.

Conquest of Persia (642 - 644)

After years of no fighting Umar now adopted a new offensive policy. The wholescale invasion of the Sassanid Empire was to begin. The Battle of Nihawand was one of the most decisive battles in Islamic history and certainly the most decisive battle in the history of Persia. More decisive than Alexander’s fatal blow at the Battle of Gaugamela, because after Gaugamela the Persians recovered within a few centuries and built an other Persian empire, but after Umar's blow to the Persians at Nihawind, the Persians would never raise another empire. The battle proved to be the key to Persia. After the devastating defeat at Nihawand, the last Sassanid emperor, Yazdgerd III, a man with iron nerves, was never able again to raise more troops to resist the mighty onslaught of Umar. It had now became a war between two rulers. Umar would follow Yazdgerd III to every corner of his empire in order to kill or capture him, like he did with Hormuzan. Yazdgerd III had a narrow escape at Marv when Umar’s lieutenant was about to capture him. He saved his life by fleeing to China, far enough from the reach of Umar. In this way the 400 years old Sassanid dynasty ultimately ended. The conquest of the Sassanid Empire was the greatest triumph of Umar, because he commanded the operations 1000 kilometers away from the battlefields and it marked his reputation as one of the greatest military and political genius of all time, like his late cousin Khalid ibn Walid (590 – 642) had proven to be.

Strategic planning for the conquest of Persia

Umar decided to strike the Persians immediately after their defeat at Nihawand now that he had gained a psychological advantage over them. The main strategic problem for Umar was from where to start the offensive. There were three alternatives: Fars in the south, Azerbaijan in the north or Isfahan in the center. Umar chose Isfahan to be the first target. His strategy was to strike the heart of the Persian Empire. This would cut off the supply lines and communication lines of the Sassanid garrisons from the rest of the Persian provinces. In order words, an attack on Isfahan would isolate Fars and Azerbaijan from Khurasan. After having captured the heart land of Persia, that is Fars and Isfahan, the next attacks would be simultaneously launched against Azerbaijan, the North Western province, and Sistan, the most Eastern province of the Persian Empire. The conquest of these provinces would leave Khurasan, the stronghold of Emperor Yazdegerd III, isolated and vulnerable. In the last phase of this grand campaign Khurasan was to be attacked. This would be the last nail in the coffin of the Sassanid dynasty. The plan was formulated and preparations were completed by January 642. The success of plan depended upon how brilliantly Umar would be able to coordinate these attacks from Madinah, about 1000 miles from the battlefields in Persia and upon the skills and abilities of his field commanders. Umar appointed his best field commanders to conquer the Sassanid Empire and bring down his most formidable foe Emperor Yazdegerd III. The campaign saw a different pattern in command structure. Umar did not appoint a single field commander to campaign across the Persian lands. He rather appointed several commanders each with their own objectives, and once the mission was over he would act as an ordinary subordinate under the new field commander for the next mission. This was done by Umar to prevent any of his commanders to gain prominence and power that could in the future threaten his own authority. In 638 he feared Khalid’s growing power and popularity and dismissed him from military services when he was at the zenith of his military career. At the time of his dismissal Khalid was more than able to rebel against Umar but he never rebelled and made a soft corner in Umar’s heart. In 642 at the eve of the conquest of Persia, Umar, wanting to give a moral boost to his troops, decided to reinstall Khalid as new field commander against Persia. Already well reputed as an invincible military commander and conqueror of the Eastern provinces of the Roman Empire, Khalid’s presence in Persia would strike terror in the Persian commanders, most of whom had already faced Khalid in 633 during his lightning conquest of Iraq. Umar wanted a sure victory in the early campaigns, which would increase the confidence of his troops and meanwhile demoralize the Persians. Unfortunately before Umar could issue orders of reappointment, Khalid, residing in Emesa, died. In various campaigns in Persia, Umar even appointed the commanders of the wings, the center and the cavalry of the army. Umar strictly instructed his commanders to consult him before making any decisive move in Persia. All the commanders, before starting their assigned campaigns were instructed to send a detailed report of the geography and terrain of the region and the position of the Persian garrisons, forts, cities and troops in it. Umar then would send them a detailed plan of how he wanted this region to be captured. Only the tactical issues were left to the field commanders to be tackled in accordance with the situation they faced at their fronts. Umar appointed the best available and well reputed commanders for the campaign.

Conquest of Central Persia (Isfahan & Tabaristan)

The ziggurat of Choqa Zanbil in Khuzestan.

The preparation and planning of conquest of Persian Empire was completed by early 642. Umar appointed Abdullah ibn Uthban, commander of the Muslim forces to invade Isfahan. From Nihawand Abdullah marched to Hamadan, which was already in Muslim hand. From Hamadan, Abdullah marched to North East to Rayy, about 200 miles from Hamadan and laid siege to the city which surrendered after fierce resistance. Once Rayy was captured Abdullah marched 230 miles south east against Isfahan city and laid siege to it, here the Muslim army was reinforced by the fresh troops from Busra and Kufa under the command of Abu Musa Ashaari and Ahnaf ibn Qais. The siege continued for few months and finally city surrendered. From Isfahan Abdullah again marched 150 miles north-east towards Qom, which was captured with out much resistance. This was the outer most boundary of Isfahan region. Further north east of it laid Khurasan, and south east of it lay Sistan. Meanwhile Hamadan and Rayy had rebelled, Umar sent Naiem ibn Muqarrin, brother of late Nauman ibn Muqarrin, who was Muslim commander at Nihawand, to crush the rebellion and clear the western most boundaries of Isfahan. Naiem marched towards Hamadan from Isfahan, a bloody battle was fought and Hamadan was recaptured by the Muslims, Naiem next moved to Rayy, here too Persians resisted and were defeated out side the fort, and city was recaptured by Muslims. Persian citizen sought for peace and agreed to pay Jizya. From Rayy, Naiem moved north towards Tabaristan, which laied south of Caspian Sea. The ruler of Tabaristan surrendered and a peace treaty was signed according to which he will govern Tabaristan on behalf of Caliph and will pay annual Jizya. This was all done in April 642. Naiem’s brother advanced further north and captured Qumas, Jarjan and Amol. He too signed a peace treaty with locals according to which they will accept the Muslim rule over area and will pay Jizya. With this campaign that ended some time 643, the Muslims were master of Tabaristan. Further North West of the region laid Azerbaijan.

Conquest of Southern Persia (Fars)

With Isfahan firmly in Muslim hand, conquest of Fars begun about the same time when conquest of Tabaristan was started. The first army that will penetrate Fars, was under the command of Maja’a ibn Masood, his objective was Sabur. Maja’a marched from Busra to Tawwaj, where Persian forces halt his way and were defeated in a quick battle thus fought. From Tawwaj Maja’a moved to Sabur, which was a fortified town. The siege continued for few weeks after which city surrendered and usual terms of Jizya were enforced on it. With the conquest of Sabur Maja’a ibn Masood’s mission was over. Reinforcement came under the command of Usman ibn Abi al-Aas, who took over the command of Majaa’s army. Usman’s objective was ancient Persian capital city of Persepolis. Usman marched from Tawwaj to Shiraz, which surrendered peacefully. From Shiraz, Usman moved 35 miles north to Persepolis and laid siege to the historic Persian city. Siege lasted for several weeks before the city surrendered. Usman’s mission was over at Persepolis. Here again a change of command occurred. The mission to captured eastern districts of Fasa and Darab was given to Sariyah ibn Zuneim, who moved 80 miles south east to capture Fasa and then Darab, 60 miles from Fasa after resistance from local Persian garrisons. With this last successful expedition, conquest of Fars was completed by late 642. Further east of Fars laid Kerman and Sistan. A simultaneous campaign was launched against eastern (sistan and Balochistan), southern (Kerman and Makran) and north western (Azerbaijan) Persia.

Conquest of Southeastern Persia (Kerman & Makran)

Sassanid era horse head Found in Kerman.

Expedition to Kerman was sent roughly at the same time when expedition to Sistan and Azerbaijan were sent. Suhail ibn adi was given command of this expedition. Suhail marched from Busra in 643, passing from Shiraz and Persepolis he join with other Muslim armies and marched against Kerman, which was subdued after a pitch battle with local garrisons. Further east of Kerman laid Makran what is now a part of present day Pakistan. It was domain of Hindu king of Rasil (sindh), who acted as a vassal of Sassanid Persians. Raja of Rasil concentrated huge armies from Sindh and Balochistan to halt the advance of the Muslims. Suhail was reinforced by Usman ibn Abi Al Aas from Persepolis, and Hakam ibn Amr from Busra, the combined forces defeated Raja Rasil at the Battle of Rasil, who retreated to the eastern bank of River Indus. Further east from Indus River laid Sindh. Umar, after knowing that sindh was a poor and relatively barran land, disapproved Suhail’s proposal to cross Indus River. For the time being, Umar declared the Indus River, a natural barrier, to be the eastern most frontier of his domain. This campaign came to an end in mid 644.

Conquest of Eastern Persia (Sistan)

Main article: History of Arabs in Afghanistan

Sistan was believed to be the largest province of the Sassanid Empire. In the south it bordered with Kerman and in the north with Khurasan. It stretches from what is now Balochistan, Pakistan in the east and southern Afghanistan in the north. Asim ibn Amr, veteran of the great battles of Qadisiyyah and Nihawand was appointed to conquer Sistan. Asim marched from Busra, and passing through Fars and taking under his command the Muslim troops already present in Fars, entered Sistan. No resistance was offered and cities surrendered. Asim reached Zaranj, 250 miles from Kandahar, a small town in present day southern Afghanistan, then a bustling capital of Sistan. Asim laid siege to the city which lasted several months. A pitch battle was fought outside the city and the Persians were defeated and routed. With the surrender of Zaranj, Sistan submitted to Muslim rule. Further east of Sistan was northern Sindh which was beyond the scope of the mission assigned to Asim. The Caliph, for the time being, didn’t approve of any incursion in the land east of the Persian Empire and ordered his men to consolidate power in the newly conquered land.

Conquest of Azerbaijan

Sassanian fortress in Derbent. It fell to the Muslims in 643.

Conquest of Azerbaijan started in 643. It was part of simultaneous attack launched against north, south and east of Persia, after capturing Isfahan and Fars. These brilliantly coordinated multi-prong attacks by Caliph Umar, paralyzed whole of what then remained of Persian Empire. Expeditions were sent against Kerman and Makran in south east, against Sistan in north east and against Azerbaijan in North West. Hudheifa ibn Al Yaman was appointed commander to conquer Azerbaijan. Hudheifa marched from Rayy in central Persia to Zanjan, a stronghold of Persians in north. Zanjan was a well defended fortified town, Persians came out of the city and gave a battle, Hudheifa defeated the Persian garrison and captured the city, as per Caliph Umar’s order, the civilians who sought for peace were given peace on the usual terms of Jizya. From Zanjan, Hudheifa marched to Ardabil which surrendered peacefully and Hudheifa continued his march north along with the western coast of Caspian Sea and captured Bab by force. At this point Hudheifa was recalled by Caliph umar. Bukair ibn Abdullah and Utba ibn Farqad succeeded him. They were sent to carry out a two prong attack against Azerbaijan. Bukair was to march north along western coast of Caspian Sea while Uthba will march direct in the heart of Azerbaijan. On his way north Bukair was halt by a large Persian force under Isandir. A pitch battle was fought and Isandir was defeated and captured. Isandir in return of safety of his life agreed to surrender his estates in Azerbaijan and persuade others for submission to Muslim rule. Uthba ibn Farqad defeated Bahram, brother of Isandir. He too sought for peace. A pact was drawn according to which Azerbaijan was surrendered to Caliph Umar on usual terms of paying annual Jizya. The espedition commenced some time in late 643.

Conquest of Armenia

View of Tbilisi, which fell to the Rashidun Caliphate in 644.

Byzantine Armenia was already conquered in 638-639. Persian Armenia lay north of Azerbaijan. By now, except for Khurasan and Armenia, the whole of the Persian Empire was under Umar’s control and Emperor Yazdegred III was on the run. Umar never wanted to take a chance; he never perceived the Persians to be weak and weary. The fact that Umar didn't underestimate the Persians is the secret behind the brilliant and speedy conquest of the Persian Empire. Again Umar decided to send simultaneous expeditions to the far north-east and north-west of the Persian Empire. An expedition was sent to Khurasan in late 643 and at the same time an expedition was launched against Armenia. Bukair ibn Abdullah, who had recently subdued Azerbaijan, was assigned a mission to capture Tiflis, the present day capital of Georgia, then a Capital of Persian Armenia. From Bab at the western coast of the Caspian Sea, Bukair continued his march north. Umar decided to practice his traditional and successful strategy of multi-pronged attacks. While Bukair was still miles away from Tiflis, Umar instructed him to divide his army into three corps. Umar appointed Habib ibn Muslaima to capture Tiflis, Abdulrehman to march north against the mountains and Hudheifa to march against the southern mountains. Habib captured Tiflis and the region up to the eastern coast of the Black Sea. Abdulrehman marched north to the Caucasus Mountains and subdued the tribes. Hudheifa marched south-west to the mountainous region and subdued the local tribes. The advance into Armenia came to an end with the death of Caliph Umar in November 644. By then almost the whole of the Caucasus was captured.

Conquest of Khurasan

Main article: History of Arabs in Afghanistan

The Shah-Do Shamshira Mosque in Kabul.

Khurasan was second largest province of Sassanid Persian Empire. It stretches from what is present day north eastern Iran, Afghanistan and Turkmenistan. Its capital was Balkh, now in present day northern Afghanistan. In late 643 the mission of conquering Khurasan was assigned to Ahnaf ibn Qais. Ahnaf marched from Kufa and took a short and less frequent route via Rayy and Nishapur. Rayy was already in Muslim hand and Nishapur surrendered with out resistance. From Nishapur Ahnaf marched to Herat which in now in present day southern Afghanistan. Herat was a fortified town, Siege of Herat lasted for few months before Herat surrendered. With the surrender of Heart, whole of the southern Khurasan came under Muslim control. With Herat under his firm control, Ahnaf marched north direct to Merv, in present Turkmenistan. Merv was the capital of Khurasan and here Yazdegred III held his court. On hearing of the Muslim advance, Yazdegred III left for Balkh. No resistance was offered at Merv, and the Muslims occupied the capital of Khurasan without firing a shot. Ahnaf stayed at Merv and waited for reinforcement from Kufa. Meanwhile Yazdgird had also gathered considerable power at Balkh and also sought alliance with the Khan of Farghana, who personally led the Turkish contingent to help Yazdegred III. Umar ordered that Yazdgird’s allied forces should be weaken by breaking up the alliance with Turks. Ahnaf successfully break up the alliance and Khan of Farghana pulled back his forces realizing that fighting with the Muslims is not a good idea and it might endanger his own kingdom. Yazdgird's army was defeated at the Battle of Oxus River and retreated across the Oxus to Transoxiana. Yazdegred III had a narrow escape and fled to China. Balkh was occupied by the Muslims, and with this occupation the Persian war was over. The Muslims had now reached the outermost frontiers of Persia. Beyond that lay the lands of the Turks and still further lay China. The old mighty empire of the Sassanids had ceased to exist. Ahnaf returned to Marv and sent a detail report of operations to Umar and a historic letter that Umar was anxiously waiting for, subject of which was that Persian Empire has been conquered and a permission was sought whether Oxus should be crossed to invade Transoxiana or not. Umar ordered Ahnaf to consolidate his power south of Oxus.

Persian rebellion

Caliph Umar was assassinated in November 644 by a Persian Slave. The assassination is often seen by various historians as a Persian conspiracy against Umar. Hormuzan is said to have masterminded this plot. Caliph Uthman ibn Affan (644-656) succeeded Umar. During his reign almost the whole of the former Sassanid empire's territory rebelled from time to time until 651, until the last Sassanid emperor was assassinated near Merv ending the Sassanid dynasty and Persian resistance to the Muslims. Caliph Uthman therefore had to send several military expeditions to crush the rebellions and recapture Persia and their vassal states. The Empire expanded beyond the borders of the Sassanid Empire in Transoxiana, Baluchistan and Caucasus. The main rebellion was in the Persian provinces of Armenia, Azerbaijan, Fars, Sistan ( in 649), Tabaristan, Khorasan (651), and Makran (650).

End of the Sassanid dynasty

Yazdegerd III, after being defeated at the Battle of Oxus river, was unable to raise another army and became a hunted fugitive. Following the battle he fled to Central asia to the court of Khan of Farghana. From there Yazdegerd went to China. Nevertheless Yazdegerd III kept on returning to Persia to exert his influence over the notables and chiefs of Persia. He thus remained a motivating force behind the Persian rebellion. During Caliph Uthman's reign Yazdegerd III came back to Bactria and Khurasan rebelled against the Caliphate. Abdullah ibn Aamir crushed the rebellion and defeated Yazdegerd's forces. He fled from one district to another until a local miller killed him for his purse at Merv in 651. For many decades to come, this was the easternmost limit of Muslim rule.

Persia under Muslim rule

See also: Islamization in Iran and Islam in Iran

Rashidun Empire at its peak under third Rashidun Caliph, Uthman- 654

  Strongholds of Rashidun Caliphate

.

View of Naqsh-e Jahan Square and Shah Mosque, Iran.

According to Bernard Lewis:

"Arab Muslims conquests have been variously seen in Iran: by some as a blessing, the advent of the true faith, the end of the age of ignorance and heathenism; by others as a humiliating national defeat, the conquest and subjugation of the country by foreign invaders. Both perceptions are of course valid, depending on one's angle of vision… Iran was indeed Islamized, but it was not Arabized. Persians remained Persians. And after an interval of silence, Iran reemerged as a separate, different and distinctive element within Islam, eventually adding a new element even to Islam itself. Culturally, politically, and most remarkable of all even religiously, the Iranian contribution to this new Islamic civilization is of immense importance. The work of Iranians can be seen in every field of cultural endeavor, including Arabic poetry, to which poets of Iranian origin composing their poems in Arabic made a very significant contribution. In a sense, Iranian Islam is a second advent of Islam itself, a new Islam sometimes referred to as Islam-i Ajam. It was this Persian Islam, rather than the original Arab Islam, that was brought to new areas and new peoples: to the Turks, first in Central Asia and then in the Middle East in the country which came to be called Turkey, and of course to India. The Ottoman Turks brought a form of Iranian civilization to the walls of Vienna."

Administration

Under Umar and his immediate successors, the Arab conquerors attempted to maintain their political and cultural cohesion despite the attractions of the civilizations they had conquered. The Arabs initially settled in the garrison towns rather than on scattered estates. The new non-Muslim subjects were protected by the state and known as dhimmi (meaning protected), were to pay a special tax, the jizya (tribute), which was calculated per individual at varying rates, usually two dirhams for able bodied men of military age, in return for their exemption from military services. Women and Children were exempted from Jizya.. Mass conversions were neither desired nor allowed, at least in the first few centuries of Arab rule Caliph Umar had liberal policies towards dhimmis, these policies were adopted to make the conquered less prone to up-rise against their new masters and thus making them more receptive to Arab colonization, as it for the time being gave them release from the intolerable social inferiority system of the old Sassanian regime. Umar is reported to have issued the following instructions about the protected people:

Make it easy for him, who can not pay tribute; help him who is weak, let them keep their titles, but do not give them our kuniyat (Arabic traditional nicknames or titles). Humiliate them but do them no injustice, if you meat them on road make them to go on sides.

Umar's liberal policies were continued by at least his immediate successors. In his dying charge to his successor he is reported to have said:

I charge the caliph after me to be kind to the dhimmis, to keep their covenant, to protect them and not to burden them over their strength.

Practically Jizya replaced poll taxes imposed by the Sassanids, which tended to be much higher than the Jizya, in addition to jizya the old Sassanid land tax (Known in Arabic as Kharaj) were also adopted. Caliph Umar is said to have occasionally setup a commission to survey the taxes, that if they are not more than the land could bear. It is narrated that Zoroastrians were subjected to humiliation and ridicule when paying the Jizya in order to make them feel inferior, and during late Abbasid they eventually lost their status as dhimmi, which forced many of them to flee to India.

For at least under Rashiduns and early Ummayads, the administrative system of the late Sassanid period was largely retained. This was a pyramidal system where each quarter of the state was divided into provinces, the provinces into districts, and the districts into sub-districts. Provinces were called ustan (Middle Persian ostan), the districts shahrs, centered upon a district capital known as shahristan. The subdistricts were called tasok in Middle Persian, which was adopted as tassuj (plural tasasij) into Arabic.

Religion

See also: Islamization in Iran and Persecution of Zoroastrians

Having effectively been recognized as dhimmis under the Rashidun Caliphs, on the terms of annual payment of Jizya, Zoroastrians were sometimes left largely to themselves, but that this pattern was patchy and varied from area to area. Due to their financial interests, Ummayads generally discourage the conversion of non-Arabs, as dhimmis provided them with valuable revenues (Jizya). With the course of time religious persecution of Zoroastrians increased, and social humiliations were implemented to make life difficult for the them and to persuade them to eventually convert to Islam.

Before the conquest, the Persians had been mainly Zoroastrian. The historian Al-Masudi, a Baghdad-born Arab, who wrote a comprehensive treatise on history and geography in about 956 A.D, records that after the conquest:

Zorastrianism, for the time being, continued to exist in many parts of Iran, not only in countries which came relatively late under Muslim sway (e.g Tabaristan) but also in those regions which early had become provinces of the Muslim empire. In almost all the Iranian provinces, according to Al Masudi, fire temples were to be found - the Madjus he says, venerate many fire temples in Iraq, Fars, Kirman, Sistan, Khurasan, Tabaristan, al Djibal, Azerbaijan and Arran.

He also added Sindh and Sin of the Indian subcontinent (Al-Hind) to the list. This general statement of al Masudi is fully supported by the medieval geographers who make mention of fire temples in most of the Iranian towns .

There were also large and thriving Christian and Jewish communities, along with smaller numbers of Buddhists and other groups. However, there was a slow but steady movement of the population toward Islam. The nobility and city-dwellers were the first to convert, Islam spread more slowly among the peasantry and the dihqans, or landed gentry. By the late 10th century, the majority of Persians had become Muslim. Until the 15th century, most Persian Muslims were Sunni Muslims, though today Iran is known as a stronghold of the Shi'a Muslim faith. The Iranian Muslims projected many of their own Persian moral and ethical values that predates Islam into the religion, while recognizing Islam as their religion and the prophet's son in law, Ali as an enduring symbol of justice.

Ancient Zorastrian Fire Temples

Place	Description	Other Information
Isthakar		Recorded in the Bam nama -a history of Kirman

Language

During the Rashidun Caliphate, the official language of Persia remained Persian. Likewise, the official languages of Syria and Egypt remained Greek and Coptic. However, during the Ummayad Caliphate, the Ummayads imposed Arabic as the primary language of their subjected people throughout their empire, displacing their indigenous languages. Although an area from Iraq to Morocco speaks Arabic to this day, Middle Persian proved to be much more enduring. Most of its structure and vocabulary survived, evolving into the modern Persian language. However, Persian did incorporate a certain amount of Arabic vocabulary, especially words pertaining to religion, and it switched from the Pahlavi Aramaic alphabet to a modified version of the Arabic alphabet.

See also

• Islamicization in post-conquest Iran
• History of Arabs in Afghanistan
• History of Iran
• Military history of Iran
• Fall of Sassanid dynasty
• Muslim conquests
• Spread of Islam
• Response from the last Persian King Yazdgird III To: Omar, Khalifat of Islam Army

Literature

• Bashear, Suliman — Arabs and Others in Early Islam, Darwin Press, 1997
• Daniel, Elton — The History of Iran, Greenwood Press, 2001
• Donner, Fred — The Early Islamic Conquests, Princeton, 1981
• M. Ismail Marcinkowski, Persian Historiography and Geography: Bertold Spuler on Major Works Produced in Iran, the Caucasus, Central Asia, India and Early Ottoman Turkey, with a foreword by Professor Clifford Edmund Bosworth, member of the British Academy, Singapore: Pustaka Nasional, 2003, ISBN 9971-77-488-7.
• Sicker, Martin — The Islamic World in Ascendancy: From the Arab Conquests to the Siege of Vienna, Praeger, 2000
• Zarrin’kub, Abd al-Husayn — Ruzgaran : tarikh-i Iran az aghz ta saqut saltnat Pahlvi, Sukhan, 1999. ISBN 964-6961-11-8
• Arab Conquest of Iran, pp. 203–10, Encyclopaedia Iranica.
• Zoroastrians: their religious beliefs and practices By Mary Boyce Rutledge Taylor and Francis group