RUDOLPH I. (1218-1291), German king, son of Albert IV. count of Habsburg, and Hedwig, daughter of Ulrich count of Kyburg, was born at Limburg, on May 1, 1218. At his father's death in 1239 Rudolph inherited the family estates in Alsace, and in 1245 married Gertrude, daughter of Burkhard III. count of Hohenberg. A partisan of the emperor Frederick II. and his son Conrad IV., he was richly rewarded by them, but in 1254 was excommunicated by Pope Innocent IV. In the general disorder after the fall of the Hohenstaufen, he increased his estates largely at the expense of his uncle, Hartmann of Kyburg, and the bishops of Strassburg and Basle, becoming the most powerful prince in south-western Germany. His election as German king at Frank furt (Sept. 29, 1273) was largely due to the efforts of his brother in-law, Frederick III. of Hohenzollern, burgrave of Nuremberg. The support of Albert duke of Saxe-Lauenburg, and of Louis II. count palatine of the Rhine and duke of upper Bavaria, had been purchased by betrothing them to two of Rudolph's daughters; so that Ottakar II. king of Bohemia, a candidate for the throne, was almost alone in his opposition. Rudolph was crowned at Aix-la Chapelle on Oct. 24, 1273. To win the approbation of the pope Rudolph renounced all imperial rights in Rome, the papal terri tory and Sicily, and promised to lead a new crusade ; and Pope Gregory X., in spite of Ottakar's protests, not only recognized Rudolph himself, but persuaded Alphonso X. king of Castile, who had been chosen German king in 1257, to do the same. From 1274-78 Rudolph was engaged in an intermittent struggle with Ottakar, which ended with the latter's death. (See AUSTRIA.) Rudolph then set about consolidating his authority in Austria and the adjacent countries, where he met much opposition. At length
in Dec. 1282 Rudolph invested his sons Albert and Rudolph with the duchies of Austria and Styria at Augsburg, and so laid the foundations of the greatness of the house of Habsburg.
In 1281 Rudolph compelled Philip I. count of upper Burgundy to cede some districts to him, forced the citizens of Berne to pay tribute, and in 1289 marched against Philip's successor, Otto IV., and compelled him to do homage. He was much less successful, however, in maintaining order in Germany, although in 1289 he led an expedition into Thuringia and destroyed some robber castles. In 1281 his first wife died, and on Feb. 5, 1284 he mar ried Isabella, daughter of Hugh IV. duke of Burgundy. In 1291 he attempted to secure the election of his son Albert as German king; but without success, although Albert, the only son who sur vived him, was crowned German king after Rudolph's death. Rudolph died at Spires on July 15, 1291 and was buried in the cathedral of that city. His reign is memorable rather for the house of Habsburg than for the kingdom of Germany.
See K. Hagen, Deutsche Geschichte von Rudolf von Habsburg bis auf die neueste Zeit (Frankfort, 1854-57) ; 0. Lorenz, Geschichte Rudolfs von Habsburg and Adolfs von Nassau (Vienna, 1863-67) ; A. Huber, Rudolf von Habsburg vor seiner Thronbesteigung (Vienna, 1873) ; J. Hirn, Rudolf von Habsburg (Vienna, ; H. von Zeiss berg, Ueber das Rechtsverfahren Rudolf von Habsburg gegen Ottokar von &Amen (Vienna, 1882) ; H. Otto, Die Beziehungen Rudolfs von Habsburg zu Papst Gregor X. (Erlangen, 1893) ; A. Busson, Der Krieg von 1278 and die Schlacht bei Diirnkrut (Vienna, 188o) ; and 0. Redlich, Rudolf von Habsburg (Innsbruck, 1903). See also GER MANY ; AUSTRIA ; HABSBURG.