Crown Prince Friedrich Wilhelm of Germany and Prussia (1882 - 1951), with his wife Cecilie of Mecklenburg-Schwerin (1886 - 1954) and their sons, Princes Wilhelm (1906 - 1940), Louis Ferdinand (1907 - 1994), Hubertus (1909 - 1950) and Friedrich (1911 - 1966), circa 1915. (Photo by Estate of Emil Bieber/Klaus Niermann/Getty Images)
