Her father was a member of David Lloyd George's coalition government during World War I and later served as Ambassador to the United States.
[2] On 16 November 1937, while travelling to London for the wedding, Prince Louis' mother, Grand Duchess Eleonore, brother, Hereditary Grand Duke Georg Donatus, sister-in-law, Hereditary Grand Duchess Cecilie, nephews, Prince Louis and Prince Alexander, and Georg Donatus' and Cecilie's newborn child, were all killed in the Sabena Junkers Ju 52 Ostend crash over Ostend, Belgium.
The day after the crash, on 17 November 1937, Margaret and Louis were married at St Peter's Church, Eaton Square.
Margaret continued to work for the German Red Cross and made Wolfsgarten available as a military hospital during the Second World War.
Queen Elizabeth II and Prince Philip called on Margaret and Louis at Wolfsgarten on 20 May 1965 during a state visit to Germany.
[1] His claim to its ancestral titles and possessions passed to Louis' adopted son Moritz, Landgrave of Hesse, head of the House of Hesse-Kassel.