|Ab urbe condita||1562|
|Balinese saka calendar||730–731|
|Chinese calendar||戊子年 (Earth Rat)|
3505 or 3445
— to —
己丑年 (Earth Ox)
3506 or 3446
|- Vikram Samvat||865–866|
|- Shaka Samvat||730–731|
|- Kali Yuga||3909–3910|
|Japanese calendar||Daidō 4|
|Minguo calendar||1103 before ROC|
|Seleucid era||1120/1121 AG|
|Thai solar calendar||1351–1352|
935 or 554 or −218
— to —
936 or 555 or −217
- Spring – Siege of Serdica: Krum, ruler (khan) of the Bulgarian Empire, captures the fortress of Serdica (modern Sofia), after a long siege. According to Byzantine sources, he massacres the garrison (supposedly 6,000 men) and razes the city walls, before returning with much loot to Bulgaria. In the following years (and centuries), Serdica will serve as a base for the expansion of the Bulgars to the south of the Balkans.
- A Byzantine fleet lands in the Venetian Lagoon, and attacks a Frankish flotilla at Comacchio, but is defeated. Doge Obelerio degli Antenori marries a Frankish bride, Carola; she becomes the first dogaressa of Venice.
- Aznar Galíndez I succeeds Aureolus, as count of Aragon (modern Spain). He is installed by King Louis the Pious (a son of emperor Charlemagne), and remains a Frankish vassal.
- A rebellion in Gharb al-Andalus (modern Portugal) is crushed by the Emirate of Córdoba.
- March 24 – Caliph Harun al-Rashid dies at Tus, on an expedition to put down an uprising in Khorasan (modern Iran). He is succeeded by his son Muhammad ibn Harun al-Amin.
- Emperor Heizei becomes ill, and abdicates the throne in favor of his brother Saga, who is installed as the 52nd emperor of Japan.
- Emperor Govinda III defeats his rival Nagabhata II, and obtains the submission of the Pala Empire (India).
- Council of Aachen (809): Frankish bishops adopt the filioque addition in the Creed. Pope Leo III intervenes, and refuses to recognize it as valid.
- March 24 – Harun al-Rashid, Muslim caliph (b. 763)
- March 26 – Ludger, Frisian missionary
- July 14 – Ōtomo no Otomaro, Japanese general and Shōgun (b. 731)
- Abbas ibn al-Ahnaf, Muslim poet (b. 750)
- Aejang, king of Silla (b. 788)
- Aureolus of Aragon, Frankish nobleman
- Cellach Tosach mac Donngaile, Irish king
- Elfodd, Welsh bishop (approximate date)
- Gang, king of Balhae (Korea)
- Wang Shizhen, Chinese general (b. 759)
- Theophanes Confessor. Chronographia, p. 485
- Fine, John V. A. Jr. (1991) . The Early Medieval Balkans: A Critical Survey from the Sixth to the Late Twelfth Century. Ann Arbor, Michigan: University of Michigan Press. p. 95. ISBN 0-472-08149-7.
- Serrão, Joel; de Oliveira Marques, A. H. (1993). "O Portugal Islâmico". Hova Historia de Portugal. Portugal das Invasões Germânicas à Reconquista (in Portuguese). Lisbon: Editorial Presença. p. 125.
- Emperor Saga, Saganoyamanoe Imperial Mausoleum, Imperial Household Agency
- The Cambridge Shorter History of India, p. 143
- Dynastic History of Magadha by George E. Somers, p. 179