816

Year 816 (DCCCXVI) was a leap year starting on Tuesday of the Julian calendar, the 816th year of the Common Era (CE) and Anno Domini (AD) designations, the 816th year of the 1st millennium, the 16th year of the 9th century, and the 7th year of the 810s decade.

Events

October 5 – King Louis the Pious (son of Charlemagne) is crowned emperor of the Holy Roman Empire, by Pope Stephen IV at Reims. He also crowns the emperor's wife Ermengarde as Holy Roman Empress. The ceremony in Reims re-establishes the principle of papal supremacy, by recognising the importance of the pope in imperial coronations. Louis gives the pope many gifts, including the estate tax Vendeuvre, near Troyes (Northern France).<ref>Salvador Miranda (1998). The Cardinals of the Holy Roman Church: Pope Stefano IV (815–817).</ref>
Vikings raid Ireland at the Kingdom of Munster, at Inish Cathaigh.<ref>Template:Cite web Retrieved on 26 July 2017.</ref>
Battle of Pancorbo: A Moorish army from the Emirate of Córdoba is sent by Emir Al-Hakam I, to take control of the pass at Pancorbo. They defeat the army of Asturian-Basque Frankish vassals.<ref>Template:Cite book</ref>
Winter – The Basques, supported by the Moors, cross the Garonne River and revolt against the Franks in Gascony (north of the Pyrenees).<ref>Islam and Europe Timeline (355–1291 AD).</ref>

King Hywel of Gwynedd is attacked by his brother Cynan on Anglesey (modern Wales), who is killed during the fighting (approximate date).

Babak Khorramdin, Persian military leader, revolts against the Abbasid Caliphate in Azerbaijan (approximate date).

Synod of Aachen: Louis the Pious calls for a council about the regulations (Institutio canonicorum Aquisgranensis) for monastic life in the Frankish Empire.
Synod of Chelsea: King Coenwulf of Mercia calls for a council about his right to appoint abbots and monasteries in England.
June 12 – Pope Leo III dies after a 20-year reign, and is succeeded by Pope Stephen IV as the 97th pope of Rome.