: 8th century
- 9th century
- 10th century
Decades: 780s 790s 800s 810s 820s - 830s - 840s 850s 860s 870s 880s
Years: 831 832 833 834 835 - 836 - 837 838 839 840 841
- Abbasid caliph al-Mutasim establishes new capital at Samarra, Iraq.
- Egbert of Wessex is defeated by the Danes.
- John VII Grammaticus succeeds Antony I as patriarch of Constantinople.
- Oldest known mentioning of the city of Soest.