[2] Fearing the rapid success of Ivaylo of Bulgaria, the Byzantine Emperor Michael VIII Palaiologos summoned Ivan Asen to his court, granted him the title of despotēs, and married him to his eldest daughter Irene Palaiologina in 1277 or 1278.
In the interval a Byzantine force besieged the Bulgarian capital Tarnovo and, hearing a rumor of Ivailo's death in battle, the local nobility surrendered and accepted Ivan Asen III as emperor in 1279.
Despairing of success, Ivan Asen III and Irene Palaiologina secretly fled Tarnovo with choice treasures from the palace treasury, including pieces captured from defeated Byzantine Emperors in former victories.
Reaching Mesembria (Nesebar), the imperial couple sailed for Constantinople, where the enraged Michael VIII refused to receive them for days for their cowardice.
In 1280 or 1281 Ivan Asen III traveled to the Golden Horde, competing with Ivailo in a bid to win support for restoration in Bulgaria.