Frederick IV (18 October 1671 – 19 July 1702) was the reigning Duke of Holstein-Gottorp. He was born in Gottorf Castle as the elder son of Duke Christian Albrecht of Holstein-Gottorp and Princess Frederika Amalia of Denmark. He was married on 12 May 1698 to Princess Hedwig Sophia of Sweden and they had an only child, Charles Frederick, who eventually fathered the future Tsar Peter III of Russia. He took part in the Great Northern War and was killed by artillery fire in the Battle of Kliszów in Poland.