William I, Elector of Hesse
William I , Elector of Hesse ( ; 3 June 1743 – 27 February 1821 ) was the eldest surviving son of Frederick II , Landgrave of Hesse-Kassel ( or Hesse-Cassel ) and Princess Mary of Great Britain , the daughter of George II . 
<triplet> William I, Elector of Hesse <subj> 3 June 1743 <obj> date of birth <subj> 27 February 1821 <obj> date of death <subj> Frederick II, Landgrave of Hesse-Kassel <obj> father <triplet> Frederick II, Landgrave of Hesse-Kassel <subj> William I, Elector of Hesse <obj> child <subj> Princess Mary of Great Britain <obj> spouse <triplet> George II <subj> Princess Mary of Great Britain <obj> child