Michael Asen III was the founder of the last ruling dynasty of the Second Bulgarian Empire, the Shishman dynasty. After he was crowned, however, Michael used the name Asen to emphasize his connection with the Asen dynasty, the first one to rule over the Second Empire.

An energetic and ambitious ruler, Michael Shishman led an aggressive but opportunistic and inconsistent foreign policy against the Byzantine Empire and the Kingdom of Serbia, which ended in the disastrous Battle of Velbazhd that claimed his own life. He was the last medieval Bulgarian ruler who aimed at military and political hegemony of the Bulgarian Empire over the Balkans and the last one who attempted to seize Constantinople. He was succeeded by his son Ivan Stephen and later by his nephew Ivan Alexander, who reversed Michael Shishman's policy by forming an alliance with Serbia.