Sigismund of Austria (October 26, 1427 in Innsbruck – March 4, 1496 ibid) was a Habsburg archduke of Austria and regent of Tirol from 1446 to 1490.
Sigismund (or Siegmund, sometimes also spelled Sigmund) was born in Innsbruck; his parents were Frederick IV of Habsburg and Anna of Braunschweig. He was a nephew of Frederick III, Holy Roman Emperor.
In 1446, his regency over Tirol and Vorderösterreich, which included the Sundgau in the Alsace, the Breisgau, and some possessions in Swabia, began. In 1449, he married Eleanor Stuart, the daughter of James I Stuart, king of Scotland.
In 1469, he gave his lands on the Rhine and in the Alsace to Charles the Bold. Sources are unclear whether he sold them due to his debts he had accumulated owing to his luxury lifestyle or just "rented" them because he wanted to have them protected better against the expansion of the Old Swiss Confederacy. In any case, he bought back this possessions in 1474, and together with the Swiss (with whom he had concluded a peace treaty in Constance) and the Alsacian cities, he sided against Charles in the Battle of Héricourt.
In 1477, Frederick III made him archduke. Three years later, Eleanor died, and 1484, Sigismund married the 16-year-old Catherine of Sachsen. He had no offspring from either marriage.
A war with Venice, which he began in 1487, ended in a standoff, but in 1490 the opposition of the population of Tirol forced him to hand over the regency to Archduke Maximilian I, who later became Holy Roman Emperor.
- Encyclopedia of Austria (http://www.aeiou.at/aeiou.encyclop.s/s575360.htm;internal&action=_setlanguage.action?LANGUAGE=en)