Serbian Campaign (World War I)
|Part of the Balkans Theatre of the First World War|
Serbian infantry, waiting for battle.
German Empire (1915–1918)
United Kingdom (1915–1918)
|Commanders and leaders|
| Oskar Potiorek
Hermann Kövess von Kövessháza
August von Mackensen
Max von Gallwitz
| Alexander I
Louis Franchet d'Espèrey
|Casualties and losses|
| 264,500+ killed and wounded (estimated)
|| 320,000 killed, wounded or diseased (estimated)
The Serbian Campaign of the First World War was fought from late July 1914, when Austria-Hungary invaded Serbia at the outset of World War I, until the war's conclusion in November 1918. The front ranged from the Danube to southern Macedonia and back north again, involving forces from almost all of the combatants of the war.
The Serbian Army declined severely towards the end of the war, falling from about 420,000 at its peak to about 100,000 at the moment of liberation. The Kingdom of Serbia lost 1,100,000 inhabitants during the war (both army and civilian losses), which represented over 27% of its overall population and 60% of its male population. According to the Yugoslav government in 1924: Serbia lost 265,164 soldiers, or 25% of all mobilized people. By comparison, France lost 16.8%, Germany 15.4%, Russia 11.5%, and Italy 10.3%.
Serbia’s defeat of the Austro-Hungarian invasion in 1914 counts among the major upset victories of the modern era.
Austria-Hungary precipitated the Bosnian crisis of 1908–1909 by officially annexing the former Ottoman territory of Bosnia and Herzegovina, which it had occupied since 1878. This angered the Kingdom of Serbia and its patron, the Pan-Slavic and Orthodox Russian Empire. Russian political manoeuvring in the region destabilised peace accords that were already unravelling in what was known as "the powder keg of Europe".
In 1912 and 1913 the First Balkan War was fought between the Balkan League and the fracturing Ottoman Empire. The resulting Treaty of London further shrank the Ottoman Empire, creating an independent Albanian State while enlarging the territorial holdings of Bulgaria, Serbia, Montenegro, and Greece. When Bulgaria attacked both Serbia and Greece on 16 June 1913, it lost most of Macedonia to Serbia and Greece, Southern Dobruja to Romania and Adrianople (which had been conquered by a combined Serbian/Bulgarian force) to Turkey in the 33-day Second Balkan War, which further destabilized the region.
On 28 June 1914, Gavrilo Princip, a Bosnian Serb student and member of Young Bosnia, assassinated the heir to the Austro-Hungarian throne, Archduke Franz Ferdinand of Austria in Sarajevo, Bosnia. The political objective of the assassination was to break the Austro-Hungarian's south-Slav provinces off from the Austro-Hungarian Empire. The assassination triggered a chain of events that embroiled Russia and the major European powers. This began a period of diplomatic manoeuvring among Austria-Hungary, Germany, Russia, France, and Britain called the July Crisis. Wanting to finally end Serbian interference in Bosnia and the Balkans, Austria-Hungary delivered the July Ultimatum to Serbia, a series of ten demands intentionally made unacceptable, intending to provoke a war with Serbia. When Serbia agreed to only eight of the ten demands, Austria-Hungary declared war on 28 July 1914. Strachan argues, "Whether an equivocal and early response by Serbia would have made any difference to Austria-Hungary's behaviour must be doubtful. Franz Ferdinand was not the sort of personality who commanded popularity, and his demise did not cast the empire into deepest mourning".
The dispute between Austria-Hungary and Serbia escalated into what is now known as World War I, which involved Russia, Germany, France, and the United Kingdom. Within a week, Austria-Hungary had to face a war with Russia, which had the largest army in the world at the time. The result was that Serbia became just another front to the massive fight that started to unfold along Austria-Hungary's border with Russia. Serbia had an experienced army, having fought two wars in the last two years, but it was also exhausted and poorly equipped, and the Austro-Hungarians thought that it would fall in less than a month. Serbia's strategy was to hold on as long as it could and hope the Russians could defeat the main Austro-Hungarian Army. Serbia constantly had to worry about its hostile neighbor to the east, Bulgaria, with which it had fought several wars, most recently in 1913.
Military forces 
The standing peace time Austro-Hungarian army ( Gemeinsame, Kaiserlich und Koniglich Heer ) counted for some 36,000 officers and NCO's and 414,000 soldiers. During the mobilization this number was increased to 3,350,000 of all ranks. The operational army had over 1,420,000 men, further 600,000 were allocated to support and logistic units ( train, munition and supply columns etc. ) while the rest, around 1,350,000 were depot troops available for replacements of losses and formation of new units.
The pre-war Austro-Hungarian plan for invasion on Serbia envisioned concentration of three armies (2nd, 5th and 6th ) on Serbian western and northern borders in order to launch a concentric offensive from two directions with main goal to envelop and destroy Serbian army. However with the beginning of Russian general mobilization AOK ( Armeeoberkommando, Austro-Hungarian Supreme command ) decided to move 2nd army to Galicia to counter Russians. Due to business of railroad lines leading to Galicia 2nd army could start its departure to Galicia only at August 18, this fact enabled AOK to allow some troops of 2nd army to take part in operations of Serbia until that date. Eventually AOK allowed Potiorek to engage significant part ( around 4 divisions ) of the 2nd army in fights against Serbia resulting in delay of transportation of these troops to Russian front for more than a week. Further more the AH defeats suffered during the first invasion of Serbia forced AOK to permanently transfer 2 divisions from 2nd army to Potiorek's force. By August 12 Austria-Hungary concentrated over 500,000 soldiers on Serbian frontiers, of which over 380,000 were operational troops. With the departure of major part of 2nd army this number fell to some 285,000 of operational troops, including the garrisons. Beside land forces A-H engaged also its Danube river flotilla of six monitors and 6 patrol boats.
The Austro-Hungarian soldiers themselves, were not of good quality. About one quarter of them were illiterate, and most of the conscripts from the Empire's subject nationalities did not speak or understand German or Hungarian. In addition to this, most of the soldiers—ethnic Czechs, Slovaks, Poles, Romanians and southern Slavs—had linguistic and cultural links with the Austro-Hungarian empire's various enemies.
Serbia declared mobilization of its armed force on July 25 with the first day of mobilization being designated for the following day, July 26. By the July 30 mobilization was completed and the troops began with concentration toward the areas of concentration defined by the war plan. The concentration was completed by August 9 with all the troops arriving on their designated positions of strategic deployment.
During the mobilization Serbia raised approximately 450,000 men of three age-defined classes or bans called poziv, which comprised all able-bodied man aging between 21 and 45 years. The operational army consisted of 11 infantry ( 6 of 1st and 5 of 2nd ban ) and 1 cavalry division. Aged men of 3rd ban were organized in 15 infantry regiments with some 45-50,000 men designated for use in rear and line of communications duties, however some of them were by necessity used as part of operational army as well, bringing up its strength up to around 250,000 men. In regard of human reserves and replacement troops Serbia was in much more disadvantageous position compared to Austria-Hungary, only source of replacements were the recruits reaching the military age, however their annual number was around 60,000 which were far from being enough to replace the loses which amounted over 132,000 just in period August-December 1914. This shortage of manpower forced Serbian army to recruit under- and over-aged men to make up the loses already in the opening phase of the war, however that will show unsustainable for longer periods of time.
Because of the poor financial state and losses in previous wars ( First and Second Balkan war ) Serbian army lacked many of the necessary weaponry and equipment. There were only 180,000 modern rifles for the operational army so the first line units lacked between one-quarter to one-third of the full number. To improve this condition Serbia ordered 120,000 rifles from Russia in 1914, however they started to arrive only in the second half of August. Only first ban troops had complete uniforms, 2nd ban troops only had greatcoats and caps while 3rd ban had no uniforms at all and wore their civil clothes; troops didn’t have service issued boots at all and vast majority of troops wore their everyday footwear made of pig skin called opanak.
The ammunition reserves were insufficient since most of the ammunition was spent in the Balkan wars. The artillery ammunition was sparse and only amounted to several hundred shells per unit; since Serbia didn’t have weapons industry worth of mention its army was completely dependent on import of ammunition and arms from France and Russia which themselves were of short supplies. This inevitably led to shortages of ammunition which later deteriorated to complete lack of artillery ammunition in the decisive moments of Austrian invasion.
Comparative strength 
Figures represent the numbers of all A-H troops concentrated on southern ( Serbian ) theater at the beginning of August and the entire Serbian army, the number of troops actually available for the operations on both sides was however somewhat lesser.
|field guns||756||558 ( 348 QF )|
Serbia's ally Montenegro mustered army of some 35-40,000 men with only 14 modern quick firing field guns and some 51 older pieces ( some of them being antique models from 1870's ) and 62 machine guns. Unlike A-H and Serbian army Montenegrin army was of militia type without proper military training and carrier officer's corps.
according to AH military formation average war strength of following units was:
engineer companies: 260
Strength of corresponding Serbian units was similar:
engineer company: 250
12 mobile batteries:
4 305 mm mortars
2 240 mm mortars
20 150 mm howitzers
16 120 mm cannons
12 mobile batteries:
6 150 mm mortars Schneider-Canet M97
22 120 mm howitzers Schneider-Canet M97
Order of battle of the Serbian army 
First Army 
General Petar Bojović, Commanding
Colonel Božidar Terzić, Chief of Staff
|Timok division I ban:
|Timok division II ban:
|Morava division II ban
Braničevo detachment (Dunav division II ban)
troops of Dunav division II ban:
Second Army 
General Stepa Stepanović, Commanding
Colonel Vojislav Živanović, Chief of Staff
|Morava division I ban
Combined division I ban
Šumadija division I ban
Dunav division I ban Milivoje Anđelković
Third army 
General Pavle Jurišić-Šturm, Commanding
Colonel Dušan Pešić, Chieff of Staff
|Divisions and brigades||Regiments|
|Drina division I ban
|Drina division II ban
Army group Užice 
General Miloš Božanović
|Divisions and brigades||Regiments|
|Šumadija division II ban
Order of battle of the Austrian-Hungarian forces at the Serbian theater , August 1914. 
Balkan force 
5. Army 
9. infantry division
21. landwehr infantry division
36. infantry division
42. honved infantry division
13. infantry brigade
11. mountain brigade
104. landsturm infantry brigade
13. march brigade
6. Army 
1. infantry division
48. infantry division
18. infantry division
47. infantry division
40. honved infantry division
109. landsturm infantry brigade
Banat Rayon and garrisons 
107. landsturm infantry brigade
sundry units of infantry, cavalry and artillery
From the 2. Army 
17. infantry division
34. infantry division
31. infantry division
32. infantry division
29. infantry division
7. infantry division
10. cavalry division
4. march brigade
7. march brigade
8. march brigade
The Serbian Campaign started on 28 July 1914, when Austria-Hungary declared war on Serbia and her artillery shelled Belgrade the following day. On August 12 the Austro-Hungarian armies crossed the border, the Drina River (see map).
Initially, three out of six Austro-Hungarian armies were mobilized at the Serbian frontier, but due to Russian intervention, the 2nd Army was redirected east to the Galician theater. However since the railroad lines leading to Galicia were busy with transport of other troops 2nd army could only start it's departure northward at August 18. In order to make use of the temporary presence of the 2nd army AOK allowed parts of it to be used in Serbian campaign until that date. Eventually AOK directed significant part of 2nd army ( around 4 divisions ) to assistance of Potiorek's main force and postponed their transportation to Russia until the last week of August, defeats suffered in the first invasion of Serbia eventually forced AOK to permanently transfer 2 divisions from 2nd army to Potiorek's army. The V and VI Austro-Hungarian armies had about 270,000 men who were much better equipped than the Serbs. Overall, Austro-Hungarian command was in the hands of general Potiorek. In addition, the Austro-Hungarian Empire had the third largest population in Europe in 1914, behind Russia and Germany, and almost twelve times the population of the Kingdom of Serbia, giving it an enormous manpower advantage.
Battle of Cer 
Potiorek rushed the attack against Serbia from northern Bosnia with his Fifth Army, supported by elements of the Second Army from Syrmia. The Second Army was due to be transported to Galicia to face the Russians at the end of August, but he made use of it until then. The Sixth was positioning itself in southern Bosnia and was not yet able to commence offensive operations. Potiorek's desire was to win a victory before Emperor Franz Joseph's birthday and to knock Serbia out as soon as possible. Thus he made two grave strategic errors, attacking with only just over half of his strength, and attacking hilly western Serbia instead of the open plains of the north. This move surprised Marshal Putnik, who expected attack from the north and initially believed that it was a feint. Once it became clear that it was the main thrust, the strong Second Army under the command of General Stepa Stepanović was sent to join the small Third under Pavle Jurišić Šturm already facing the Austro-Hungarians and expel the invaders. After a fierce four-day battle, the Austro-Hungarians were forced to retreat, marking the first Allied victory of the war. Casualties numbered 23,000 for the Austro-Hungarians (of whom 4,500 were captured) and 16,500 for the Serbs.
Battle of Drina 
Under pressure from its allies, Serbia conducted a limited offensive across the Sava river into the Austro-Hungarian region of Syrmia with its Serbian First Army. The main operational goal was to delay the transport of the Austro-Hungarian Second Army to the Russian front. The objective was shown to be futile as forces of the Second Army were already in transport. Meanwhile the Timok division I of the Serbian Second Army suffered a heavy defeat in a diversionary crossing, suffering around 6,000 casualties while inflicting only 2,000.
With most of his forces in Bosnia, Potiorek decided that the best way to stop the Serbian offensive was to launch another invasion into Serbia to force the Serbs to recall their troops to defend their much smaller homeland.
7 September brought a renewed Austro-Hungarian attack from the west, across the river Drina, this time with both the Fifth Army in Mačva, and the Sixth further south. The initial attack by the Fifth Army was repelled by the Serbian Second Army, with 4,000 Austro-Hungarian casualties, but the stronger Sixth Army managed to surprise the Serbian Third Army and gain a foothold. After some units from the Serbian Second Army were sent to bolster the Third, the Austro-Hungarian Fifth Army also managed to establish a bridgehead with a renewed attack. At that time, Marshal Putnik withdrew the First Army from Syrmia (against much popular opposition) and used it to deliver a fierce counterattack against the Sixth Army that initially went well, but finally bogged down in a bloody four-day fight for a peak of the Jagodnja mountain called Mačkov Kamen, in which both sides suffered horrendous losses in successive frontal attacks and counterattacks. Two Serbian divisions lost around 11,000 men, while Austro-Hungarian losses were probably comparable.
Marshal Putnik ordered a retreat into the surrounding hills and the front settled into a month and a half of trench warfare, which was highly unfavourable to the Serbs, who had little in the way of an industrial base and were deficient in heavy artillery, ammunition stocks, shell production (having only a single factory producing around 100 shells a day) and also footwear, since the vast majority of infantry wore the traditional (though state-issued) opanaks, while the Austro-Hungarians had waterproof leather boots. Most of their war material was supplied by the Allies, who were short of such materials themselves. In such a situation, Serbian artillery quickly became almost silent, while the Austro-Hungarians steadily increased their fire. Serbian casualties reached 100 soldiers a day from all causes in some divisions.
During the first weeks of trench warfare, the Serbian Užice Army (one strengthened division) and the Montenegrin Sanjak Army (roughly a division) conducted an abortive offensive into Bosnia. In addition, both sides conducted a few local attacks, most of which were soundly defeated. In one such attack, the Serbian Army used mine warfare for the first time: the Combined Division dug tunnels beneath the Austro-Hungarian trenches (that were only 20–30 meters away from the Serbian ones on this sector), planted mines and set them off just before an infantry charge.
Battle of Kolubara 
Having thus weakened the Serbian army, the Austro-Hungarian Army launched another massive attack on November 5. The Serbs withdrew step by step, offering strong resistance at the Kolubara River, but to no avail, due to the lack of artillery ammunition. It was at that time that General Živojin Mišić was made commander of the battered First Army, replacing the wounded Petar Bojović. He insisted on a deep withdrawal in order to give the troops some much-needed rest and to shorten the front. Marshal Putnik finally relented, but the consequence was the abandonment of the capital city of Belgrade. After suffering heavy losses, the Austro-Hungarian Army entered the city on December 2. This move led Potiorek to move the whole Fifth Army into the Belgrade area and use it to crush the Serbian right flank. This, however, left the Sixth alone for a few days to face the whole Serbian army.
At this point, artillery ammunition finally arrived from France and Greece. In addition, some replacements were sent to the units and Marshal Putnik correctly sensed that the Austro-Hungarian forces were dangerously overstretched and weakened in the previous offensives, so he ordered a full-scale counterattack with the entire Serbian Army on December 3 against the Sixth Army. The Fifth hurried its flanking maneuver, but it was already too late – with the Sixth Army broken, the Second and Third Serbian Armies overwhelmed the Fifth. Finally, Potiorek lost his nerve and ordered yet another retreat back across the rivers into Austria-Hungary's territory. The Serbian Army recaptured Belgrade on December 15.
The first phase of the war against Serbia had ended with no change in the border, but casualties were enormous compared to earlier wars, though sadly, not out of keeping with other campaigns of this war. The Serbian army suffered 170,000 men killed, wounded captured or missing. Austro-Hungarian losses were approaching 215,000 men killed, wounded or missing. Austro-Hungarian General Potiorek was removed from command and replaced by Archduke Eugen of Austria (C. Falls p. 54). On the Serbian side, a deadly typhus epidemic killed hundreds of thousands of Serb civilians during the winter.
Early in 1915, with the Ottoman defeats at the Battle of Sarikamis and in the First Suez Offensive, German Chief of the General Staff Erich von Falkenhayn tried to convince the Austro-Hungarian Chief of Staff, Conrad von Hötzendorf, of the importance of conquering Serbia. If Serbia were taken, then the Germans would have a rail link from Germany, through Austria-Hungary and down to Istanbul (and beyond). This would allow the Germans to send military supplies and even troops to help the Ottoman Empire. While this was hardly in Austria-Hungary's interests, the Austro-Hungarians did want to defeat Serbia. However, Russia was the more dangerous enemy, and furthermore, with the entry of Italy into the war on the Allied side, the Austro-Hungarians had their hands full (see the Italian Campaign (World War I)).
Both the Allies and the Central Powers tried to get Bulgaria to pick a side in the Great War. Bulgaria and Serbia had fought two wars in the last 30 years: the Serbo-Bulgarian War in 1885, and the Second Balkan War in 1913. The result was that the Bulgarian government and people felt that Serbia was in possession of lands to which Bulgaria was entitled, and when the Central Powers offered to give them what they claimed, the Bulgarians entered the war on their side. With the Allied loss in the Battle of Gallipoli and the Russian defeat at Gorlice, King Ferdinand signed a treaty with Germany and on September 23, 1915 and Bulgaria began mobilizing for war.
Opposing forces 
During the preceding nine months, the Serbs had tried, and failed, to rebuild their battered armies and improve their supply situation. Despite their efforts, the Serbian Army was only about 30,000 men stronger than at the start of the war (around 225,000) and was still badly equipped. Although Britain and France had talked about sending serious military forces to Serbia, nothing was done until it was too late. When Bulgaria began mobilizing, the French and British sent two divisions, but they arrived late in the Greek town of Salonika. Part of the reason for the delay was the Greek government's conflicted views about the war.
Against Serbia were marshalled the Bulgarian First Army, the German Eleventh Army and the Austro-Hungarian Third Army, all under the command of Field Marshal Mackensen. In addition the Bulgarian Second Army, which remained under the direct control of the Bulgarian high command, was deployed against Macedonia.
Course of the Campaign 
The Austro-Hungarians and Germans began their attack on 7 October, with their troops crossing the Drina and Sava rivers, covered by heavy artillery fire. Once they crossed the Danube, the Germans and Austro-Hungarians moved on Belgrade itself. Vicious street fighting ensued and the Serbs' resistance in the city was finally crushed on 9 October.
Then, on 14 October, the Bulgarian Army attacked from two directions, from the north of Bulgaria towards Niš and from the south towards Skopje (see map). The Bulgarian First Army defeated the Serbian Second Army at the Battle of Morava, while the Bulgarian Second Army defeated the Serbians at the Battle of Ovche Pole. With the Bulgarian breakthrough, the Serbian position became untenable; the main army in the north (around Belgrade) could either retreat, or be surrounded and forced to surrender. In the Battle of Kosovo the Serbs made a last and desperate attempt to join the two incomplete Allied divisions that made a limited advance from the south, but were unable to gather enough forces, due to the pressure from the north and east and were halted by the Bulgarians under General Georgi Todorov and had to pull back.
Marshal Putnik ordered a full retreat, south and west through Montenegro and into Albania. The weather was terrible, the roads poor, and the army had to help the tens of thousands of civilians who retreated with them with almost no supplies or food left. But the bad weather and poor roads worked for the refugees as well, as the Central Powers forces could not press them hard enough, and so they evaded capture. Many of the fleeing soldiers and civilians did not make it to the coast, though – they were lost to hunger, disease, attacks by enemy forces and Albanian tribal bands. The circumstances of the retreat were disastrous, and all told, only some 155,000 Serbs, mostly soldiers, reached the coast of the Adriatic Sea, and embarked on Allied transport ships that carried the army to various Greek islands (many to Corfu) before being sent to Salonika. The survivors were so weakened that thousands of them died from sheer exhaustion in the weeks after their rescue. Marshal Putnik had to be carried during the whole retreat and he died a bit more than a year later in a hospital in France.
The French and British divisions marched north from Salonika in late November under the command of French General Maurice Sarrail. However, the British divisions were ordered by the War Office in London not to cross the Greek frontier. So the French divisions advanced on their own up the Vardar River. This advance was of some limited help to the retreating Serbian Army as the Bulgarian Army had to concentrate some forces on their southern flank to deal with the threat (see: Battle of Krivolak). By mid-November, General Sarrail concluded that a retreat was necessary in the face of determined Bulgarian assaults on his positions.
This was a nearly complete victory for the Central Powers at a cost of around 67,000 casualties as compared to around 90,000 Serbs killed or wounded and 174,000 captured. The railroad from Berlin to Istanbul was finally opened. The only flaw in the victory was the remarkable retreat of the Serbian Army, which was almost completely disorganized and had to be rebuilt almost from scratch.
In 1917, the Serbs launched the Toplica Uprising and liberated for a short time the area between the Kopaonik mountains and the South Morava river. The uprising was crushed by joint efforts of Bulgarian and Austrian forces at the end of March 1917.
The Macedonian Front in the beginning was mostly static. French and Serbian forces retook limited areas of Macedonia by recapturing Bitola on 19 November 1916 as a result of the costly Monastir Offensive which brought stabilization of the front.
Serbian and French troops finally made a breakthrough, after most of the German and Austro-Hungarian troops had withdrawn. This breakthrough was significant in defeating Bulgaria and Austro-Hungary, which led to the final victory of World War I. The Bulgarians suffered their only defeat of the war at the Battle of Dobro Pole but days later, they decisively defeated British and Greek forces at the Battle of Doiran, avoiding occupation. After the Allied breakthrough, Bulgaria capitulated on 29 September 1918. Hindenburg and Ludendorff concluded that the strategic and operational balance had now shifted decidedly against the Central Powers and a day after the Bulgarian collapse, during a meeting with government officials, insisted on an immediate peace settlement.
The disappearance of the Macedonian Front meant that the road to Budapest and Vienna was now opened for the 670,000-strong army of general Franchet d'Esperey as the Bulgarian surrender deprived the Central Powers of the 278 infantry battalions and 1,500 guns (the equivalent of some 25 to 30 German divisions) that were previously holding the line. The German high command responded by sending only seven infantry and one cavalry division but these forces were far from enough for a front to be reestablished.
The Serbian Army, aided by the British and the French, pushed forward and eventually managed to liberate Serbia two-weeks before the end of the War.
End of the War 
The ramifications of the war were manifold. When World War I ended, the Treaty of Neuilly gave Greece Western Thrace, and Serbia some minor territorial concessions from Bulgaria. Austria-Hungary was broken apart and Hungary lost much land to both Yugoslavia and Romania in the Treaty of Trianon. Serbia assumed the lead position in the new state of Yugoslavia, joined by its old ally, Montenegro. Meanwhile, Italy established a quasi-protectorate over Albania and Greece reoccupied the country's southern part, which was autonomous under a local Greek provisional Government (see Autonomous Republic of Northern Epirus).
Before the war, the Kingdom of Serbia had 4,500,000 inhabitants. According to the New York Times, in 1915 alone 150,000 people are estimated to have died during the worst typhus epidemic in world history. With the aid of the American Red Cross and 44 foreign governments, the outbreak was brought under control by the end of the year. The number of civilian deaths is estimated by some sources at 650,000, primarily due to the typhus outbreak and famine, but also direct clashes with the occupiers. Serbia's casualties accounted for 8% of the total Entente military deaths. 58% of the regular Serbian Army (420,000 strong) perished during the conflict. The total number of casualties is placed around 1,000,000: 25% of Serbia's prewar size, and an absolute majority (57%) of its overall male population. L.A. Times and N.Y. Times also cited over 1,000,000 victims in their respective articles.
The extent of the Serbian demographic disaster can be illustrated by the statement of the Bulgarian Prime Minister Vasil Radoslavov: "Serbia ceased to exist" (New York Times, summer 1917). In July 1918 the US Secretary of State Robert Lansing urged the Americans of all religions to pray for Serbia in their respective churches.
Serbia suffered enormous casualties. The Serbian Army had been decimated towards the end of the war, falling from about 420,000 at its peak to about 100,000 at the moment of liberation.
The Kingdom of Serbia lost 1,100,000 inhabitants during the war (both army and civilian losses: of 4.5 million people, 275,000 were military deaths, while 450,000 were civilian – mostly due to food shortages, epidemics and the Spanish flu—and there were 133,148 wounded), which represented over 15% of its overall population—a demographic disaster that is still obvious today. According to the Yugoslav government in 1924, Serbia lost 365,164 soldiers, or 26%, of all mobilized personnel, while France suffered 16.8%, Germany 15.4%, Russia 11.5%, and Italy 10.3%.
At the end of the war, there were 114,000 disabled soldiers and 500,000 orphaned children. (cit. Serbian History : Duško M. Kovačević, Dejan Mikavica, Branko Bešlin, Biljana Šimunović-Bešlin)
Attacks against ethnic-Serb civilians 
||The neutrality of this section is disputed. (November 2012)|
The Assassination of Archduke Franz Ferdinand of Austria and Sophie, Duchess of Hohenberg in Sarajevo led to angry Croats and Muslims engaging in violent anti-Serb demonstrations during the evening of June 28 and for much of the day during the 29th of June. These events led to a deep division along ethnic lines that was unprecedented in the city's history. This was because most Croats and many Muslims considered that the Archduke represented the best chance for the establishment of a South Slav political entity within the Habsburg Empire. The crowd directed its anger principally at shops owned by ethnic-Serbs and at residences of prominent Serbs. The mob attacked the cluster of structures near the New Serbian Orthodox Church, threw stones at the metropolitan's residence and sacked the Serbian Orthodox School. Other smaller groups stoned the building that housed the Serb cultural society Prosvjeta, sacked a Serb bank, and trashed the offices of the newspaper Srpska Riječ. They singled out shops of Serb merchants including the family business of one of the men who was involved in the Archduke's assassination, Neđeljko Čubrinović, and attacked Serb residences. Two ethnic-Serbs were killed that day by crowd violence. That night there were anti-Serb demonstrations in other parts of the Austro-Hungarian Empire.
Incited by anti-Serbian propaganda and ordered by the command of the Austro-Hungarian Army, soldiers committed numerous atrocities against the Serbian people on the territory of Serbia and Austria-Hungary. According to the German criminologist and observer R.A. Reiss, it was a "system of extermination". In addition to executions of prisoners of war, civilian populations were subjected to mass murder and rape. Villages and towns were burned and looted. Fruit trees were cut down and water wells were poisoned in an effort on the Austro-Hungarian part to get the Serb inhabitants to not return. Also, the invading Bulgarian Army committed numerous atrocities, particularly in Niš and the town of Surdulica.
See also 
- Österreich-Ungarns letzter Krieg — Wien: Verlag der Militärwissenschaftlichen Mitteilungen, 1930. — Vol. 1. pg. 759. This is the total number of soldiers who served on the Balkans until the middle of December 1914.
- Thomas & Babac. "Armies in the Balkans 1914–1918" pg.12
- Георги Бакалов, "История на Българите: Военна история на българите от древността до наши дни", p.463
- Чедомир Антић, Судњи рат, Политика од 14. септембра 2008.
- Владимир Радомировић, Највећа српска победа, Политика од 14. септембра 2008.
- John R. Schindler, "Disaster on the Drina: The Austro-Hungarian Army in Serbia, 1914," War In History (April 2002) 9#2 pp 159–195 
- Keegan 1998, pp. 48–49
- Willmott 2003, pp. 2–23
- Willmott 2003, p. 26
- Willmott 2003, p. 27
- Strachan 2003, p. 68
- Österreich-Ungarns letzter Krieg 1914 - 1918, vol. 1, Wienn 1930, p68
- http://honsi.org/literature/svejk/dokumenty/oulk/band1.html Österreich-Ungarns letzter Krieg 1914 - 1918, vol. 1, Wienn 1930, p68
- Jordan 2009, p. 20
- Willmott 2009, p. 69
- James Lyon, A peasant mob: The Serbian army in the eve of the Great War, JMH 61, 1997, p501
- James Lyon, p496
- Österreich-Ungarns letzter Krieg 1914 - 1918, vol. 1, Wienn 1930, p68
- Österreich-Ungarns letzter Krieg 1914 - 1918, vol. 1, Wienn 1930, p.82
- Gordon Martel, The Origins of the First World War, Pearson Longman, Harlow, 2003, p. xii f.
- Jordan 2008, p. 25
- Jordan 2008, p. 31
- Jordan 2008, p. 53
- Willmott 2008, p. 120
- Tucker & Roberts 2005, pp. 1075–6
- Spencer Tucker, "Encyclopedia of World War I"(2005) pg 1077, ISBN 1851094202
- Tucker, Wood & Murphy 1999, p. 120
- Pyrrhic victory: French strategy and operations in the Great War, Harvard University Press, 2005;, 2005, p. 491, ISBN 978-0-674-01880-8, retrieved 3 October 2010
- "The Balkan Front of the World War (in Russian)". militera.lib.ru. Retrieved 27 September 2010.
- Mitrović 2007, pp. 223.
- Serbia in 1914
- "$1,600,000 was raised for the Red Cross" (PDF). The New York Times. 29 October 1915.
- Serbian army, August 1914
- Tema nedelje: Najveća srpska pobeda: Sudnji rat: POLITIKA
- Тема недеље : Највећа српска победа : Сви српски тријумфи : ПОЛИТИКА (Serbian)
- Fourth of Serbia's population dead.
- Asserts Serbians face extinction
- Serbia restored
- "Serbia and Austria" (PDF). New York Times. 28 July 1918.
- "Appeals to Americans to pray for Serbians" (PDF). New York Times. 27 July 1918.
- Sarajevo: a biography, by Robert J. Donia. Google Books. 29 June 1914. Retrieved 16 January 2012.
- Beginning the twentieth century: a history of the generation that made the war, by Joseph Ward Swain. Google Books. Retrieved 16 January 2012.
- Yugoslavia's bloody collapse: causes, course and consequences, by Christopher Bennett. Google Books. Retrieved 16 January 2012.
- How Austria-Hungary waged war in Serbia (1915) German criminologist R.A. Reiss on atrocities by the Austro-Hungarian army
- Augenzeugen. Der Krieg gegen Zivilisten. Fotografien aus dem Ersten Weltkrieg Anton Holzer, Vienna
- Photos of Austrian atrocities in Serbia
- Falls, Cyril, The Great War (1960)
- Esposito, Vincent (ed.), The West Point Atlas of American Wars – Vol. 2; maps 46–50. Frederick Praeger Press (1959)
- Österreich-Ungarns letzter Krieg 1914 - 1918, vol. 1, Wienn 1930 
- Jordan, David (2008). The Balkans, Italy & Africa 1914–1918: From Sarajevo to the Piave and Lake Tanganyika. London, United Kingdom: Amber Books Ltd. ISBN 978-1-906626-14-3.
- Mitrović, Andrej (2007). Serbia's Great War, 1914-1918. West Lafayette, Indiana: Purdue University Press. ISBN 978-1-55753-476-7.
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