He was also declared porphyrogennetos (porfirorodnij and bagrenorodnij in Bulgarian sources from 1272/3 and 1303) in accordance with Byzantine practice, perhaps to block any potential older sons of Constantine Asen I from inheriting the throne.
[3] His mother Maria was apparently working to ensure his unchallenged possession of the throne in the face of Constantine Asen's political and physical weakness.
When Constantin Asen was killed in battle against Ivailo in 1277, young Michael was left as the legitimate emperor of Bulgaria, under the guidance of his mother Maria.
Already chafing under Ivailo's rule, and now presuming or pretending that he had died, the city nobles opened the gates of Tărnovo to the besieging Byzantine army and accepted Ivan Asen III as emperor in February 1279.
"[11] This attempt to recover the Bulgarian throne is associated with a poorly preserved rock inscription from the cave monasteries by the village of Royak, naming "the porphyrogennetos emperor Michael.