Frederick IV (king of Denmark and Norway)
Frederick IV, 1671–1730, king of Denmark and Norway (1699–1730), son and successor of Christian V. He allied himself (1699) with Augustus II of Poland and Saxony and with Peter I of Russia against Charles XII of Sweden in the Northern War, but was forced to sign the humiliating Treaty of Travendal in 1700. Still hoping to recover S Sweden (lost in 1660) and to assure Danish rule in Schleswig, he again entered the war in 1709. In the peace treaties of 1720–21, Denmark renounced S Sweden but obtained Schleswig. Frederick was industrious and able. He systematized absolute monarchy, reduced corruption, built schools, attempted to repair the damage caused by the war, and reduced the national debt. He was succeeded by his son, Christian VI.