| Millennium: | 1st millennium |
|---|---|
| Centuries: | 8th century – 9th century – 10th century |
| Decades: | 780s 790s 800s – 810s – 820s 830s 840s |
| Years: | 809 810 811 – 812 – 813 814 815 |
| 812 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 812 DCCCXII |
| Ab urbe condita | 1565 |
| Armenian calendar | 261 ԹՎ ՄԿԱ |
| Bahá'í calendar | -1032 – -1031 |
| Bengali calendar | 219 |
| Berber calendar | 1762 |
| Buddhist calendar | 1356 |
| Burmese calendar | 174 |
| Byzantine calendar | 6320 – 6321 |
| Chinese calendar | 辛卯年十二月十三日 (3448/3508-12-13) — to —
壬辰年十一月廿四日(3449/3509-11-24) |
| Coptic calendar | 528 – 529 |
| Ethiopian calendar | 804 – 805 |
| Hebrew calendar | 4572 – 4573 |
| Hindu calendars | |
| - Bikram Samwat | 868 – 869 |
| - Shaka Samvat | 734 – 735 |
| - Kali Yuga | 3913 – 3914 |
| Holocene calendar | 10812 |
| Iranian calendar | 190 – 191 |
| Islamic calendar | 196 – 197 |
| Japanese calendar | |
| Korean calendar | 3145 |
| Thai solar calendar | 1355 |