FREDERICK WILLIAM III, King of Prussia. — Born 3 Aug. 1770 at Potsdam, died 7 June 1840 at Berlin. Ascending the throne in 1797, he ceded in 1801, by the Treaty of Lunéville, the lands on the left bank of the Rhine to France, but two years later, through the secularization of the German ecclesiastical states, he obtained as compensation the bishoprics of Hildesheim, Paderborn, Münster and other territories. Forced in 1807 into the disastrous Peace of Tilsit and in 1812 into alliance with France, F. W. took advantage of Napoleon’s defeat in Russia to free himself from the French yoke. Declaring war on France, F. W., together with the emperors of Austria and Russia, entered Paris in triumph.
After the Congress of Vienna he remained ever faithful to the policy of the Holy Alliance.
Attached to Lutheranism, he was concerned by the large number of conversions to the Catholic faith among Prussian citizens who were going to Rome at that time. He wished to establish a German evangelical community in the Eternal City. In 1839 he sought to promote the union of Calvinists with the Lutherans of his kingdom by constituting the Evangelical Church of Prussia (Evangelische Kirche der Altpreussischen Union). Toward Catholicism the king was steadfastly hostile, hindering in various ways the bishops in the exercise of their ministry and tending to reduce the Church to a mere appendage of the state.