Donatus Landgraf von Hessen was born on 17 October 1966 in Kiel, Schleswig-Holstein, West Germany. He has been married to Floria-Franziska Marie-Luise Erika von Faber-Castell since 23 April 2003. They have three children.
4th cousin of King Charles III through both of Charles' parents; Donatus' great-uncle Prince Christoph of Hesse was also married to Charles' aunt, Princess Sophie of Greece and Denmark, one of Prince Philip's sisters.