Ivan Asen II of Bulgaria
Michael was the son of Ivan Asen II of Bulgaria and Irene Komnene Doukaina. He was most probably born in 1239. His father, who died in the first half of 1241, was succeeded by Michael's seven-year-old half-brother, Kaliman. Kaliman died unexpectedly (possibly of poisoning, according to contemporaneous rumors) in August or September 1246.