 His brother-in-law, Prince Philip of Greece and Denmark, fought on the British side and married the future Queen Elizabeth II after the war.Prince Christoph of Hesse was born in Frankfurt, the fifth son of Prince Frederick Charles of Hesse and Princess Margaret of Prussia.His father, Frederick Charles, a scion of the House of Hesse, was elected King of Finland in 1918, when Finland declared its independence after the collapse of the Russian Empire.