815
Year 815 was a common year starting on Monday of the Julian calendar, the 815th year of the Common Era and Anno Domini designations, the 815th year of the 1st millennium, the 15th year of the 9th century, and the 6th year of the 810s decade.
Events
By place
Byzantine Empire
- Byzantine–Bulgarian Treaty: Emperor Leo V the Armenian signs a 30-year peace agreement in Constantinople with Omurtag, ruler of the Bulgarian Empire. The Rhodope Mountains become the Byzantine border again, and Leo regains its lost Black Sea cities, after the Bulgars have them demolished.
Central America
- April 2 - Sihyaj K'in Ich’aak II becomes the new ruler of the Mayan city state of Machaquila in Guatemala after the death of Ochk'in Kaloomte' Aj Ho' Baak, and reigns until early 824.
Europe
- Hrafna-Flóki Vilgerðarson sets out from the Faroe Islands and discovers Iceland .
Britain
- King Egbert of Wessex ravages the territories of the remaining British kingdom Dumnonia, known as the West Welsh.
Asia
- Emperor Saga of Japan is the first sovereign to drink tea, imported from China by monks. The upper classes adopt this beverage for medicinal use.
- July 13 - Wu Yuanheng, Chinese chancellor of the Tang Dynasty, is murdered by assassins of warlord Wu Yuanji, in Chang'an.
By topic
Religion
- Synod of Constantinople: A council led by patriarch Theodotus I, in the Hagia Sophia, reinstitutes iconoclasm.
Births
- Abu Hanifa Dinawari, Muslim botanist and geographer
- Boniface VI, pope of the Catholic Church
- Dawud al-Zahiri, Muslim scholar
- Eberhard, duke of Friuli
- Johannes Scotus Eriugena, Irish theologian
- Leoluca, Sicilian abbot
- Methodius, Byzantine missionary and bishop
- Theodora, Byzantine empress
Deaths
- February 15 - Ibn Tabataba, Zaydi anti-caliph
- July 13 - Wu Yuanheng, chancellor of the Tang Dynasty
- October 18 - Abu'l-Saraya, Zaydi rebel leader
- Jābir ibn Hayyān, Muslim alchemist
- Laylā bint Ṭarīf, Arab woman warrior poet
- Mashallah ibn Athari, Jewish-Arab astrologer
- Muirgius mac Tommaltaig, king of Connacht
- Omar Tiberiades, Persian astrologer
- Sadnalegs, emperor of Tibet