Who is the mother of XXX?
Johann Leopold, Hereditary Prince of Saxe-Coburg and Gotha
Johann Leopold, Hereditary Prince of Saxe-Coburg and Gotha (Johann Leopold William Albert Ferdinand Victor; 2 August 1906 -- 4 May 1972) was the eldest son of Charles Edward, Duke of Saxe-Coburg and Gotha and Princess Victoria Adelaide of Schleswig-Holstein-Sonderburg-Glücksburg.