FREDERICK IV. elector palatine of the Rhine, only surviving son of the elector Louis VI., was born at Amberg on March 5, 15 74. His uncle and guardian, John Casimir, brought him up as a Lutheran. In January 1592, on the death of John Casimir, Frederick undertook the government of the Pala tinate, and continued the policy of his uncle, hostility to the Catholic Church and the Habsburgs, and co-operation with foreign Protestants. He was often in communication with Henry of Na varre, afterwards Henry IV. of France, and like him was unre mitting in his efforts to conclude a league among the German Protestants, while he sought to weaken the Habsburgs by refusing aid for the Turkish War. After many delays and disappointments the Union of Evangelical Estates was actually formed in May 1608, under the leadership of the elector. Frederick married in Louise, daughter of William the Silent, prince of Orange. He died on Sept. 19, 161o.