Decades: 770s 780s 790s 800s 810s - 820s - 830s 840s 850s 860s 870s

Years: 815 816 817 818 819 - 820 - 821 822 823 824 825

• Michael II succeeds Leo V as Byzantine Emperor

• Rhodri the Great, ruler of Wales (approximate date)
• Photius I, patriarch of Constantinople (approximate date)

• December 24: Leo V, Byzantine Emperor (assassinated)
• Shankara, Hinduist teacher
• Tang Xian Zong, emperor of China (end of reign)\n