History
820
General
Population: 225 Million*
- Language: Old French divides from Latin
- Mathematics: Persian mathematician Musa al-Chwarazmi develops Algebra
- Religion: Abbassid caliphate ends – start Taherite dynasty at Khurasan
- Deaths: Constantine I of Scotland, Byzantine emperor Leo V
Europe
- Scotland: Death of Constantine I of Scotland
Middle East
- Byzantine Empire: death of Leo V Byzantine emperor
Michael II the Amorian becomes Byzantine Emperor (end of Syrian and start of Phrygian dynasty)