Keratsa of Bulgaria byzantine nun and empress (1348–1390) Parents Sarah-Theodora Ivan Alexander of Bulgaria Children John VII Palaiologos Siblings Desislava of Bulgaria Ivan Asen V of Bulgaria Ivan Shishman of Bulgaria Vasilisa of Bulgaria Ivan Asen IV of Bulgaria Michael Asen IV of Bulgaria Ivan Sratsimir of Bulgaria Kera Tamara Mara (?) Partners Andronikos IV Palaiologos