From Infogalactic: the planetary knowledge core
|Centuries:||8th century – 9th century – 10th century|
|Decades:||790s 800s 810s – 820s – 830s 840s 850s|
|Years:||826 827 828 – 829 – 830 831 832|
|829 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||1582|
|Chinese calendar||戊申年 (Earth Monkey)
3525 or 3465
— to —
己酉年 (Earth Rooster)
3526 or 3466
|- Vikram Samvat||885–886|
|- Shaka Samvat||751–752|
|- Kali Yuga||3930–3931|
|Japanese calendar||Tenchō 6
|Minguo calendar||1083 before ROC
|Seleucid era||1140/1141 AG|
|Thai solar calendar||1371–1372|
- October 2 – Emperor Michael II dies after a 8-year reign in Constantinople and is succeeded by his 16-year-old son Theophilos as sole emperor of the Byzantine Empire. He continues his fathers ideology of iconoclasm.
- October – Battle of Thasos: Saracens from the newly found Emirate of Crete almost annihilate the Byzantine fleet at Thasos, close to the coast of Thrace. The Cyclades and other islands in the Aegean Sea are pillaged.
- Emperor Louis the Pious appoints his 6-year-old son Charles by his second wife Judith, as ruler of the Frankish subkingdom Alamannia. Enraging his eldest son Lothair I and co-emperor, who begins to insurrect.
- Giustiniano Participazio, doge of Venice, dies after a 2-year reign and is succeeded by his younger brother Giovanni Participazio. He continues the work of Giustiniano in construction of the St. Mark's Basilica.
- King Egbert of Wessex invades Mercia, ousts his rival Wiglaf and attemps to rule directly from Wessex. He is recognized as overlord (bretwalda) of other English kingdoms.
- Winter – Battle of the River Dore: Egbert of Wessex leads his army against the Northumbrians as far as Dore, were he clashes with king Eanred of Northumbria.
- Ansgar, Frankish abbot of Corvey (modern Westphalia), is appointed missionary to Sweden by emperor Louis the Pious, at the request of the Swedish king Björn at Haugi.
- The city of Wiesbaden (Germany) is first mentioned by Einhard, biographer of former emperor Charlemagne (approximate date).
- Cui Zhi, chancellor of the Tang Dynasty (b. 772)
- Giustiniano Participazio, doge of Venice
- October 2 – Michael II, emperor of the Byzantine Empire (b. 770)
- Wei Chuhou, chancellor of the Tang Dynasty (b. 773)
- Zheng Yin, chancellor of the Tang Dynasty (b. 752)
- Timothy E. Gregory, A History of Byzantium, (Blackwell Publishing Ltd, 2010), p. 227.
- Treadgold, Warren (1988). The Byzantine Revival, 780–842, Stanford University Press, p. 268. ISBN 0-8047-1462-2.
- Lamb, H. H. (1977) Climate: Present, Past and Future: Climatic History and the Future Vol 2, Methuen and Co. Ltd., London.