Constantine

Constantine was the only son of the Vidin tsar Ivan Sratsimir, proclaimed by his father co-ruler with the imperial title. The Vidin metropolitan Joasaph relates how Ivan Sratsimir sent him, together with the prelate, to Tarnovo "for imperial affairs, needful and great" — a mission on which the two obtained the relics of St Philothea and translated them to Vidin.

The destruction of the Vidin tsardom by the Ottomans at the end of 1396 turned Constantine from heir to the throne into an exile. While his father fell into captivity, he managed to escape and sought refuge first in Hungary and then in Serbia, at the court of Despot Stefan Lazarević; in a Latin source he is named "Constantinus, imperator Bulgariae magnificus."

When, after Bayezid's defeat at Ankara (1402), the Ottomans sank into civil war, the anti-Turkish forces of the Balkans revived. Around 1408 the first Bulgarian anti-Ottoman rising broke out, known as the "uprising of Constantine and Fružin": Constantine acted in the Vidin region, and his cousin Fružin in the Tem region and eastern Bulgaria. The struggle lasted until about 1413, when Musa finally broke the resistance and devastated the Bulgarians. Constantine remained the last bearer of the imperial title of medieval Bulgaria.