Her paternal grandparents were William, German Crown Prince, and Duchess Cecilie of Mecklenburg-Schwerin. Maternally, she is a granddaughter of Cyril Vladimirovich, Grand Duke of Russia, and Princess Victoria Melita of Saxe-Coburg and Gotha.
Marie-Cécile is in the line of succession to the British throne. 28 May 1942 - 3 December 1965: Her Royal Highness Princess Marie Cécile of Prussia 3 December 1965 - 23 November 1989: Her Royal Highness Duchess Friedrich August of Oldenburg 23 November 1989 – present: Her Royal Highness Princess Marie Cécile of Prussia.
