Ernest Louis was the last Grand Duke of Hesse and by Rhine. He was the fourth child and eldest son of Grand Duke Louis IV and Princess Alice of the United Kingdom, daughter of Queen Victoria and Prince Albert of Saxe-Coburg and Gotha. He was an older brother to Tsarina Alexandra Feodorovna (née Alix of Hesse), Empress consort of Tsar Nicholas II of Russia
Queen Louise of Denmark, 1817-1898, nee Louise of Hesse-Cassel. Grandmother of Europe. Wife of Christian IX, they had 6 children: Frederick VIII of Denmark, father of Christian X, and Haakon VII of Norway; Queen Alexandra, mother of George V, and Maud, Queen of Norway; George I of Greece, father of Constantine I; Dagmar (Marie Feordorovna) of Russia, mother of Tsar Nicholas II; Thyra, Crown Princess of Hanover and Duchess of Brunswick; and Prince Valdemar. They had 39 grandchildren.
Princess Victoria of Hesse, Prince Louis of Battenberg and their four children Princess Alice of Battenberg, Louise, George and Louis. The Battenberg family changed their name to Mountbatten during WWI.