He was elected Palatine of Hungary in 1519 but the opposition of the nobility, which accused him of avarice and licentiousness, resulted in his being temporarily deposed in 1523 and 1525.
In 1526, he fought in the disastrous Battle of Mohács against the Turks, in which King Louis II fell.
Stephen managed to escape and became one of the leaders of the pro-Austrian party that wanted to honour the alliance between now extinct royal family and the Habsburg dynasty.
His siding with the Habsburgs cost him all his possessions within Turkish-controlled Hungary, for which Ferdinand compensated him with the castle Theben.
Their daughter Clara was engaged to be married to Duke Carl of Münsterberg but died before the marriage, in 1535.