| Friedrich Karl Ludwig | |
| Succession: | Duke of Schleswig-Holstein-Sonderburg-Beck |
| Reign: | 24 February 1775 March 1816 |
| Predecessor: | Peter August |
| Successor: | Friedrich Wilhelm |
| House: | Schleswig-Holstein-Sonderburg-Beck |
| Birth Date: | 20 August 1757 |
| Birth Place: | Königsberg, Prussia |
| Death Place: | Wellingsbüttel Manor, Hamburg |
| Father: | Prince Karl Anton August of Schleswig-Holstein-Sonderburg-Beck |
| Mother: | Countess Charlotte of Dohna-Schlodien |
Friedrich Karl Ludwig, Duke of Schleswig-Holstein-Sonderburg-Beck (; 20 August 175724 April 1816)[1] was the ninth and penultimate Duke of Schleswig-Holstein-Sonderburg-Beck. Friedrich Karl Ludwig was the son of Prince Karl Anton August of Schleswig-Holstein-Sonderburg-Beck and his wife Countess Charlotte of Dohna-Schlodien.
Friedrich Karl Ludwig was born in Königsberg, Kingdom of Prussia. At the age of two he lost his father who died from wounds he received in the battle of Kundersdorf. He joined the Prussian Army in 1777 upon the request of King Frederick the Great. By 1781 he was a staff officer in the Regiment von Schlieben and by 1787 he commanded a grenadier battalion based in Königsberg. He assisted in the suppression of the 1794 Kościuszko Uprising and was Governor of Kraków in 1795. He retired from Prussian service as a lieutenant general in 1797 and spent the rest of his life improving agriculture in Holstein.[1] He died in Wellingsbüttel Manor, now part of Hamburg.
He was a recipient of the Order of the Elephant, Order of St. Alexander Nevsky, Order of the Red Eagle, and the Order of Saint Hubert.[2]
Friedrich married Countess Friederike of Schlieben on 8 March 1780 in Königsberg. She was the second and youngest daughter of Count Karl Leopold of Schlieben and his wife, Countess Marie Eleonore von Lehndorff.
At the time, the marriage was not looked upon favorably by his family, because the Schlieben family, although a noble one, didn't belong to an exclusive circle of either reigning families or ancient noble families, which would be more acceptable. Friedrich and Friederike had three children:
Friedrich was succeeded as duke by his son, Friedrich Wilhelm, Duke of Schleswig-Holstein-Sonderburg-Glücksburg.