800s (decade)

Europe

Charlemagne, emperor (king) of the Franks

• December 25 – Charlemagne, king of the Franks, is crowned Holy Roman Emperor by Pope Leo III as Charles I, with the title "Emperor of the Franks and the Lombards". The coronation takes place during Mass at the Basilica of St. Peter in Rome, on Christmas Day. The Frankish Empire is formed in Western Europe, which is not recognized by Empress Irene at Constantinople. This triggers a series of disputes with the Byzantines around who is officially ruling the former Western Roman Empire. ^[1]
• The Rus' Khaganate (modern Ukraine) is created by people who are called Rus', after the 182-year dominance of the Khazars. This is the starting period of the rise of the Kievan Rus', and the later states of Belarus and Ukraine (approximate date).
• King Eardwulf of Northumbria has his men seize prince Ealhmund, son of the late king Alhred, and put him to death. He is buried at Derby in St. Alkmund's Church, and later revered as a saint (approximate date).

Asia

• The ci, a new type of lyric poetry with irregular lines, is set to a melody during the Tang Dynasty (approximate date).

Africa

• Sijilmasa (in present-day Morocco) is founded as the departure point, for caravans between North Africa and the western Sudan (approximate date).
• Ife, in present-day Nigeria, becomes an important urban center (approximate date).

Mesoamerica

• Itza culture starts in Mesoamerica (approximate date).

Polynesia

• The first settlers of the Hawaiian Islands arrive (approximate date).

Religion

• Archbishop Hygeberht of Lichfield retires; he is succeeded by Ealdwulf. King Coenwulf of Mercia is on better terms with the archepiscopal of Canterbury than his predecessor, and unsuccessfully attempts to have the Mercian archepiscopal see transferred to London (approximate date).
• The Book of Kells is written and illuminated in a Columban monastery, in the British Isles (approximate date).

== {{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}} == {{trim|{{transcluded-section|{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}}} {{#section-h::{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}|Events}}}} == {{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}} == {{trim|{{transcluded-section|{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}}} {{#section-h::{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}|Events}}}} == {{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}} == {{trim|{{transcluded-section|{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}}} {{#section-h::{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}|Events}}}} == {{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}} == {{trim|{{transcluded-section|{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}}} {{#section-h::{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}|Events}}}} == {{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}} == {{trim|{{transcluded-section|{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}}} {{#section-h::{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}|Events}}}} == {{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}} == {{trim|{{transcluded-section|{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}}} {{#section-h::{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}|Events}}}} == {{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}} == {{trim|{{transcluded-section|{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}}} {{#section-h::{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}|Events}}}} == {{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}} == {{trim|{{transcluded-section|{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}}} {{#section-h::{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}|Events}}}} == {{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}} == {{trim|{{transcluded-section|{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}}} {{#section-h::{{dr|y|y|{{{year}}}0|{{{1}}}|n{{#ifexpr:{{{year}}}<10|a}}}}|Events}}}}