Who was the legal grandson of the Earl of Merica?
Ealdgyth, daughter of Earl Ælfgar Ealdgyth ("fl. c". 1057–1066), also Aldgyth or in modern English, Edith, was a daughter of Ælfgar, Earl of Mercia, the wife of Gruffudd ap Llywelyn (d. 1063), ruler of all Wales, and later the wife and queen consort of Harold Godwineson, king of England in 1066. She was described by William of Jumièges as a considerable beauty.
Henry Percy, 3rd Earl of Northumberland Henry Percy, 3rd Earl of Northumberland, (25 July 1421 – 29 March 1461) was an English magnate.