Background
Marianne was born at Kamieniec Palace in Kamenz, Kingdom of Prussia, (now Kamieniec Ząbkowicki, Poland) third daughter of Prince Friedrich Wilhelm of Prussia (1880–1925), (son of Prince Albert of Prussia and Princess Marie of Saxe-Altenburg) and his wife, Princess Agatha of Hohenlohe-Schillingsfürst (1888–1960) (daughter of Victor II, Duke of Ratibor and Countess Maria Breunner-Enkevoirth).