Maria was a Bulgarian princess and daughter of Emperor Ivan Asen II (r. 1218–1241) and Irene Komnene. As a child of her father's third marriage, she was born sometime between 1238 and 1241.^[1] Through her mother, Maria was a granddaughter of Emperor Theodore Komnenos Doukas of Thessalonica (r. 1215–1230, d. after 1253) and Maria Petraliphaina. Maria was the full sister of Emperor Michael Asen I of Bulgaria and of Anna/Theodora.^[2] Maria is traditionally identified as the spouse of Emperor Mitso Asen of Bulgaria (r. 1256–1257), and thus a Bulgarian empress consort, but this is not certain.

The sources name two sons-in-law of Ivan Asen II among the Bulgarian aristocracy, the sebastokrator Peter and the future emperor Mitso Asen. They seem to have married Ivan Asen II's daughters by Irene Komnene,^[3] but no source specifies the names of their respective wives.^[4] The renowned Bulgarian historian Vasil Zlatarski, without much rationale, assigned Anna/Theodora as the wife of Peter and Maria as the wife of Mitso Asen.^[5] Since Ivan Božilov adopted this solution, albeit without much conviction,^[6] this had become the common assumption in Bulgarian historiography.^[7] Considering onomastic patterns and the implication of the names of Peter and Mitso Asen's descendants, Ian Mladjov argued that the opposite arrangement, with Maria marrying Peter and Anna/Theodora marrying Mitso Asen, is more likely and preferable.^[8]

The wife of sebastokrator Peter, traditionally identified as Anna/Theodora but perhaps more likely Maria, had an unnamed daughter, who married despotes Shishman of Vidin and founded the Shishman branch of the Asenid dynasty. She was the grandmother of Emperor Michael Asen III "Shishman" (r. 1323–1330) and great-grandmother of Emperor Ivan Alexander of Bulgaria (r. 1331–1371).^[9] On the other hand, the wife of Mitso Asen, traditionally identified as Maria but perhaps more likely Anna/Theodora, was the mother of Emperor Ivan Asen III of Bulgaria (r. 1279–1280) and of Maria, the second wife of Emperor George Terter I of Bulgaria (r. 1280–1292), and the ancestress of the Byzantine branch of the Asenid dynasty.^[10]