|802 by topic|
|Ab urbe condita||1555|
|Balinese saka calendar||723–724|
|Chinese calendar||辛巳年 (Metal Snake)|
3498 or 3438
— to —
壬午年 (Water Horse)
3499 or 3439
|- Vikram Samvat||858–859|
|- Shaka Samvat||723–724|
|- Kali Yuga||3902–3903|
|Japanese calendar||Enryaku 21|
|Minguo calendar||1110 before ROC|
|Seleucid era||1113/1114 AG|
|Thai solar calendar||1344–1345|
928 or 547 or −225
— to —
929 or 548 or −224
Year 802 (DCCCII) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar.
- October 31 – Empress Irene is deposed after a 5-year reign, and banished to Lesbos. High-ranking patricians place Nikephoros, the minister of finance (logothetes tou genikou), on the throne. He is crowned in the Hagia Sophia at Constantinople, by Patriarch Tarasios, as emperor of the Byzantine Empire.
- May 1 – Lachan Kʼawiil Ajaw Bot (born June 25, 760) becomes the ruler of the Mayan city state near Itzan in Guatemala.
- Pagan Danes invade Obodrite-ruled Schleswig, to take over territory almost emptied by the forcible deportations of the Saxons by emperor Charlemagne.
- Al-Andalus: Saragossa rises against the Emirate of Córdoba. Emir Al-Hakam I sends a Muslim army under General Amrus ibn Yusuf, and retakes the city.
- Krum becomes ruler (khan) of the Bulgarian Empire (until 814). During his reign Bulgarian territory doubles in size, from the Danube to the Dniester.
- King Beorhtric of Wessex dies after drinking a chalice of poison intended for his wife, Eadburh. She flees to the court of Charlemagne, who accepts a portion of her wealth and makes her abbess. Prince Egbert returns to Wessex, and is accepted as the new king.
- Battle of Kempsford: Æthelmund, ealdorman of Hwicce, is killed during the battle by his rival Weohstan, who levies West Saxon Wiltshire.
- The Vikings plunder the treasures of Iona Abbey, on the west coast of Scotland (approximate date).
- The Mecca Protocol: Caliph Harun al-Rashid and the leading officials of the Abbasid Caliphate perform the hajj to Mecca, where the line of succession is finalized. Harun's eldest son al-Amin is named heir, but his second son al-Ma'mun is named as al-Amin's heir, and ruler of a broadly autonomous Khurasan. A third son, al-Qasim, is added as third heir, and receives responsibility over the frontier areas with the Byzantine Empire.
- Prince Jayavarman declares the Khmer Empire (modern-day Cambodia) independent, and establishes the kingdom of Angkor. He is reconsecrated as a world ruler (chakravartin), or god-king (devaraja), under Hindu rites.
- The Haeinsa Temple of the Jogye Order is built in Korea.
- Bi Xian, chancellor of the Tang Dynasty (d. 864)
- Fujiwara no Nagara, Japanese statesman (d. 856)
- Hugh, illegitimate son of Charlemagne (d. 844)
- Ono no Takamura, Japanese scholar and poet (d. 853)
- Ralpacan, emperor of Tibet (d. 836)
- January 11 – Paulinus II, patriarch of Aquileia (or 804)
- Æthelmund, Anglo-Saxon nobleman
- Bahlul ibn Marzuq, Muslim general
- Beorhtric, king of Wessex
- Domitian, duke of Carantania (approximate date)
- Eadburh, Anglo-Saxon princess
- Kardam, ruler (khan) of the Bulgarian Empire (or 803)
- Rashid, Muslim regent of Idris II
- Višeslav, duke of Croatia (or 810)
- Wulfstan, Anglo-Saxon ealdorman
- Theoctista, politically influential Byzatine woman (b. 740)
- ^ Nicolle 2014, p. 21.
- ^ Rucquoi 1993, p. 87.
- ^ Kirby, Earliest English Kings, p. 186.
- ^ Williams, Smyth & Kirby, A Biographical Dictionary of Dark Age Britain (1991), p. 24.
- ^ Gilbert Meynier (2010) L'Algérie cœur du Maghreb classique. De l'ouverture islamo-arabe au repli (658-1518). Paris: La Découverte; pp.28.
- Nicolle, David (2014). The Conquest of Saxony AD 782–785. ISBN 978-1-78200-825-5.
- Rucquoi, Adeline (1993). Histoire médiévale de la Péninsule ibérique (in French). Paris: Seuil. p. 87. ISBN 2-02-012935-3.