Shishman, king Michael III Shishman Assen's third son from his marriage with Ana-Neda, sought asylum with the Tatars and appeared in Constantinople as a pretender for the Bulgarian Throne in the summer of 1341. The Bulgarian king Ivan Alexander insisted on the Byzantines' deporting his "worst enemy from the Shishmans", but the empire, reluctant to miss the opportunity to interfere into the its northern neighbour's internal affairs, threatened to send Shishman with a fleet to Bdin where he could rely on support "because of his old friendship and family relations". There was no development of the king's demand, and there are no further records of his life.
Unreliable records state that Joseph II, Patriarch of Constantinople (1416-1439), was Shishman II's illegitimate son.