820

Asia

 * , the son of a slave, is rewarded with the governorship of because he have supported the . He rules independently of, not even mentioning the caliph's name in Friday prayers in recognition of caliphal authority.

Byzantine Empire

 * succeeds Leo V as Byzantine Emperor.

Europe

 * The is written (approximate date)
 * assumes the

Science & Technology

 * mathematician founded.

Births

 * ('the Great'), ruler of  (approximate date) (d. )
 * , (approximate date) (d. )

Deaths

 * —, (b. )
 * , (end of reign)