863Centuries: 8th century - 9th century - 10th century
- Constantine I succeeds as king of Scotland. (or 862)
- Pope Nicholas I excommunicates patriarch Photius I of Constantinople.
- After the death of Charles, Lothair takes part of the Jura and Louis II takes the Provence.
- Carloman revolts against his father Louis the German a second time.
- Cyril and Methodius mission in Great Moravia begins