Frederick Louis, Duke of Schleswig-Holstein-Sonderburg-Beck (; 6 April 1653 – 7 March 1728) was a Duke of Schleswig-Holstein-Sonderburg-Beck and field marshal of the Prussian Army.
Early life
Frederick Louis was born in Haus Beck (now part of Löhne), near Ulenburg, Westphalia, Margraviate of Brandenburg, as the son of August Philipp, Duke of Schleswig-Holstein-Sonderburg-Beck and his wife, Countess Marie Sibylle of Nassau-Saarbrücken.
Biography
He was only the titular duke, because he did not inherit the domain of Beck. It had been inherited by Duke Frederick William I, the son of his elder brother, Duke August, in 1689. Duke Frederick William I was killed in the Battle of Francavilla in Sicily in 1719, leaving a widow, née Maria Antonia called Antoinette Josepha Isnardi di Castello, Contessa di Sanfré (1692–1762), and two minor daughters. In 1675 he participated in the Battle of Fehrbellin as a Rittmeister. The following year he was a colonel in the Holstein dragoons. Frederick Louis was named lieutenant general and Governor of Wesel in 1690. Three years later he was appointed commanding general of the Duchy of Prussia.
On 17 January 1701 Frederick Louis received the Order of the Black Eagle from the new King Frederick I of Prussia and shortly afterward was named Statthalter of the Kingdom of Prussia and Governor of Königsberg. During the War of the Spanish Succession, he participated in the Battle of Oudenarde in 1708, the Battle of Malplaquet in 1709, and the sieges of Lille, Mons, and Tournai.