Of the House of Hapsburg, founder of the Austrian dynasty; born, the son of a count, at Schloss Limburg (Breisgau); greatly increased his father's domain by marriage, inheritance, and conquest, becoming the most powerful prince in S. Germany; acquired a remarkable ascendency among the German princes, and was elevated to the imperial throne in 1273, and by friendly concessions to the Pope, Gregory IX., terminated the long struggle between the Church and the empire; shattered the opposition of Ottocar, king of Bohemia, and brought peace and order to Germany (1218-1291).