Years: 826 827 828 829 - 830 - 831 832 833 834

Decades: 800s 810s 820s - 830s - 840s 850s 860s

Centuries: 8th century - 9th century - 10th century

Events

• Christian missionary Ansgar visits Birka, trade city of the Swedes.
• Earliest date of composition for the Historia Brittonum, attributed to Nennius, and known for its list of 12 battles of King Arthur.
• Censored page defeats the Welsh.
• Al-Khwarizmi writes the Hisab 'al-jabr' w?al-muqabala, an important work on algebra.
• Borobodur is completed as a Buddhist monument, after about 50 years of work.

Births

• Emperor Koko of Japan
• Carloman, King of Bavaria

Deaths

• Saint Glastian , mediator between Scots and Picts