Michael I - Augustus of Basileía Rhōmaíōn from 811 to 813
Michael I was Byzantine Emperor from 811 to 813. He was the son of the patrician Theophylact Rhangabe, the admiral of the Aegean fleet. He married Prokopia, the daughter of the future Emperor Nikephoros I, and received the high court dignity of kouropalatēs after his father-in-law's accession in 802.

Michael survived Nikephoros' disastrous campaign against Krum of Bulgaria, and was considered a more appropriate candidate for the throne than his severely injured brother-in-law Staurakios. When Michael's wife Prokopia failed to persuade her brother to name Michael as his successor, a group of senior officials forced Staurakios to abdicate in his favor on 2 October 811.

In 813 he was defeated by the Bulgarians, and with conspiracy in the air, Michael preempted events by abdicating in favor of the general Leo the Armenian and becoming a monk (under the name Athanasios). His sons were castrated and relegated into monasteries. Michael died peacefully in 844.
Michael I
Emperor Michael I of the Byzantine Empire