When the Carinthian counts of Ortenburg became extinct in 1418, their estates were bequested to the Counts of Celje. Count Ulrich II was even elevated to a Prince of the Holy Roman Empire by the Emperor Sigismund, but left no heirs when he was killed by his bitter rival Ladislaus Hunyadi in 1456. He had signed an inheritance treaty with the Habsburg emperor Frederick III, also Duke of Carinthia since 1424. However, the Meinhardiner count John II of Görz also claimed the former Ortenburg dominions. He marched against Carinthia from his Tyrolean residence at Bruck Castle, crossing the border at Oberdrauburg and occupying Spittal to lay siege to the Ortenburg fortress. He was finally defeated in 1460 and had to sign the Treaty of Pusarnitz at episcopal Feldsberg Castle, whereby he renounced all Carinthian estates in favour of the Austrian House of Habsburg.