During the Second World War, Moritz's mother, Princess Mafalda of Savoy, was arrested by the Nazis for alleged subversive activities and died in the Buchenwald concentration camp in 1944 as a result of a U.S. bombing raid on the camp.

Moritz and his siblings (Moritz, Otto and Elisabeth) were given sanctuary in the Vatican under the care of their Aunt and Uncle Louis, Prince of Hesse and by Rhine and Margaret Campbell Geddes who adopted them.

Together with his younger brothers, he took part in the ship tour organized by Queen Frederica and her husband King Paul of Greece in 1954, which became known as the “Cruise of the Kings” and was attended by over 100 royals from all over Europe.

Moritz had been the head of the House of Hesse since the death of his father Philip on 25 October 1980.

Moritz married Princess Tatiana of Sayn-Wittgenstein-Berleburg, daughter of Prince Gustav Albrecht.