Following the death of his father, Duke Frederick IV, Sigismund (also called Siegmund) became a ward of his cousin, Emperor Frederick III. In 1446 he assumed the regency in Tyrol and the Swabian territories. He promoted the mining industry and grew rich on its profits, but also accumulated large debts. In 1490 he fell into severe difficulties and had to hand Tyrol over to King Maximilian I. The extravagance of his court earned him the epithet ‘Rich in Coin’.