the surviving younger brothers Frederick and Ernest again divided the Leopoldian possessions. With Further Austria, Frederick became undisputed ruler over the Habsburg territories in the Alsace region and of the Burgau margraviate. In 1417 he also inherited the former Kyburg estates from the extinct comital Habsburg-Laufenburg branch. Several border conflicts with the Republic of Venice led to the loss of Rovereto in the Lagarina Valley. Under the terms of the Western Schism, Duke Frederick sided with Antipope John XXIII, whom he helped on his flight from the Council of Constance in March 1415. The Luxembourg king Sigismund had John arrested in Breisgau and placed Frederick under the Imperial ban. Thanks to the support of the local populace he managed to keep Tyrol, though he lost the western Aargau, the Freiamt and County of Baden estates, in the old homeland of the Habsburgs, to the Swiss. In 1420, Frederick also moved his Tyrolean court from Meran to Innsbruck. After several rebellions by local nobles, his rule over Tyrol had stabilized, partially due to the successful beginning of silver mining that brought an increase in prosperity to the region. After the death of his brother Ernest on 10 June 1424, Duke Frederick also took over the regency over Inner Austria for his minor nephews Frederick V (the later Emperor Frederick III) and Albert VI. In his later years, however, he again had to cope with another rebellion against his Tyrolean rule, instigated by Prince-Bishop Alexander of Trent. Frederick died at his court in Innsbruck, despite his nickname a rich man. His son and heir Sigismund was called der Münzreiche ("Rich in Coin"). Frederick was buried in the Cistercian abbey of Stams, Tyrol. Marriage and issue On 24 December 1407, Frederick married Elizabeth of the Palatinate (1381–1408), daughter of King Rupert of Germany, in Innsbruck. They had one daughter, Elizabeth, but both mother and child died shortly after the birth on 27 December 1408. On 11 June 1411, Frederick married Anna (d. 1432), daughter of the Welf duke Frederick I of Brunswick-Wolfenbüttel; they had: Margaret (14231424) Hedwig (14241427) Wolfgang (1426) Sigismund (14271496). Only Sigismund survived until adulthood. He succeeded his father in Tyrol and Further Austria. Ancestors References Sources External links Encyclopedia of Austria Austria, Friedrich IV of Austria, Friedrich IV of 15th-century dukes of Austria Counts of Tyrol