Hunyadi family
Count Ulrich II of Cilli was the most powerful member of the Cilli family. In 1432 he married Catherine, daughter of the Serbian despot Đurađ Branković. Ulrich held a large influence in many courts, which originated from the relationships the Cilli family had made in the past. Upon the death of the Habsburg king Albert II in 1439, he tried to get regency of Hungary, Bohemia and Austria through control over Albert's minor son Ladislaus the Posthumous. With such ambitions he got many opponents and rivals, such as the Hungarian Hunyadi family. After an unsuccessful claim to the Bosnian crown, Cilli obtained some territories in Croatia and Slavonia and in 1452 finally succeeded in forcing Emperor Frederick III to hand over the boy king Ladislaus to his keeping. Thus, Ulrich II became "de facto" regent of Hungary.