Frederick William was 19 years older than the princess and he was called the "mad Margrave" because of his pranks and rude manners. Their relationship was not happy, and eventually they lived in separate places: Sophie lived in the castle Montplaisir near the residence, and the Margrave lived in the castle of Schwedt.
married first 1951, Princess Ortrud of Schleswig-Holstein-Sonderburg-Glücksburg; had issue. married second 1981, Countess Monika zu Solms-Laubach; no issue. Prince George William: 25 March 1915 8 January 2006 (aged 90) married 1946, Princess Sophie of Greece and Denmark; had issue. Frederica, Queen of the Hellenes: 18 April 1917