Siege of Belgrade
In 1452, he forced Emperor Frederick III of Habsburg to hand over the boy king Ladislaus to his keeping, practically making him ruler of Hungary. In 1454 his power was increased by his succession to his father's vast wealth; and after the death of John Hunyadi at the Siege of Belgrade in 1456, he was named Captain General of Hungary by Ladislaus, an office previously held by his rival.