Sigismund (Innsbruck, October 26, 1427 - Innsbruck, March 4, 1496) Austrian duke, then archduke and (duke) count of Tyrol from 1446 to 1490, IV. He was the son of Frederick and Anne of Braunschweig. Cousin of Frederick V (German-Roman Emperor under the name Frederick III), who was his guardian and regent until 1446 after his father's death. In 1446, Sigismund gained power in Tyrol, Lower Austria and some Swabian territories. In 1449, he married he married Eleonora Stuart, daughter of King James I of Scotland, who was brought up in the French court. Her first marriage remained childless for a long time, and then the Archduchess, who was already over 40, gave birth to a son, Archduke Wolfgang, but she died with the child shortly after the birth (in 1480. In 1469, she sold her lands along the Rhine to Duke Károly Merész of Burgundy. The reasons are not entirely clear, but it was probably due to his debts, which were accumulated from maintaining the luxurious court. However, he managed to buy back the sold estates in 1474. In 1477, his cousin Frederick III raised Sigismund to the rank of archduke. In the late 1470s or the 80s At the beginning of this period, Sigismund issued a decree introducing the first really high silver currency in history, the guldengroschen, which was used by the Habsburgs in Bohemia before the thaler. The widow Sigismund then married the then 16-year-old Catherine of Saxony, the daughter of Prince Albert of Saxony and the Czech royal princess Sidonia Podjebrád He had no children from his second marriage. Sigismund waged war with Venice, but it ended in a stalemate.

At the end of the 1470s or the beginning of the 80s, Archduke Sigismund issued a decree in which he introduced the first money with a really high silver content in history, the guldengroschen, which was used by the Habsburgs in Bohemia before the thaler. It was the predecessor of most of the coins used later in Europe.