referred to Frederick I as "the mercenary king", due to the fact that he greatly profited from the hiring of his Prussian troops to defend other territories, such as in northern Italy against the French. "All in all," he wrote of his grandfather, "he was great in small matters, and small in great matters." Marriages and children Frederick was married three times: first to Elizabeth Henrietta of Hesse-Kassel (1661-1683), with whom he had one child, Louise Dorothea, born 1680, who died without issue at age 25. then to Sophia Charlotte of Hanover (1668-1705), with whom he had Frederick August (1685–1686) Frederick William I, born in 1688, who succeeded him. In 1708, he married Sophia Louise of Mecklenburg-Schwerin, who survived him but had no children by him. He also had an official mistress, Catharina von Wartenberg, between 1696 and 1711. However, he was never known to make use of her services, being deeply in love with his second wife. Ancestry Notes Further reading Dwyer, Philip G., ed. The Rise of Prussia, 1700–1830 (2000). Frey, Linda, and Marsha Frey. Frederick I: The Man and His Times (1984). External links |- |- |- Kings of Prussia 1657 births 1713 deaths 17th-century Dukes of Prussia 18th-century Kings of Prussia Brandenburg-Prussia Dukes of Prussia Electoral Princes of Brandenburg Prince-electors of Brandenburg House of Hohenzollern Princes of Neuchâtel German landowners German Calvinist and Reformed Christians People from the Duchy of Prussia Nobility from Königsberg Garter Knights appointed by William III Burials at Berlin Cathedral 17th-century German military personnel 18th-century German military personnel Brandenburgian nobility German people of Dutch descent German people of Portuguese descent German army commanders in the War of the Spanish Succession Military personnel from Königsberg