Konstantin-Assen, Prince of Vidin Bulgarian prince (b. 1967) Parents Queen Margarita of Bulgaria Simeon II of Bulgaria Children Prince Umberto of Bulgaria Princess Sofia of Bulgaria Siblings Kyril, Prince of Preslav Kardam, Prince of Tarnovo Kubrat, Prince of Panagyurishte Princess Kalina of Bulgaria Partners Maria Garcia de la Rasilla y de Gortazar