Katarina Branković, also known as Kantakuzina was the Countess of Celje, through the marriage with Count of Celje Ulrich II. A Serbian princess, she was the daughter of Despot Đurađ Branković and Byzantine princess Irene Kantakouzene. She is remembered for writing the Varaždin Apostol (1454), and her endowment of the Rmanj Monastery.
Portrait from Esphigmenou monastery (1429)
Medvedgrad was one of Katarina's possessions
Church of Saint Stephen in Konče
The Counts of Celje or the Counts of Cilli were the most influential late medieval noble dynasty on the territory of present-day Slovenia. Risen as vassals of the Habsburg dukes of Styria in the early 14th century, they ruled the County of Cilli as immediate counts (Reichsgrafen) from 1341. They soon acquired a large number of feudal possessions also in today's Croatia and Bosnia. They rose to Princes of the Holy Roman Empire in 1436. The dynasty reached its peak with Ulrich II of Cilli, but with his death in 1456 they also died out, and after a war of succession, the Habsburgs inherited their domains.
Celje Castle
Counts of Cilli (bottom row, second right) in the structure of the Holy Roman Empire