Who was the legal grandson of the Earl of Merica?
Ælfgar, Earl of Mercia Ælfgar (died c. 1060) was the son of Leofric, Earl of Mercia, by his famous mother Godgifu (Lady Godiva). He succeeded to his father's title and responsibilities on the latter's death in 1057. He gained the additional title of Earl of East Anglia, but also was exiled for a time. Through the first marriage of his daughter he would become father-in-law of the Welsh king Gruffydd ap Llywelyn; a few years after his death, his daughter would become a widow and marry English King Harold.
Duchy of Cornwall The Duchy of Cornwall (Cornish: Duketh Kernow ) is one of two royal duchies in England, the other being the Duchy of Lancaster. The eldest son of the reigning British monarch inherits possession of the duchy and title of Duke of Cornwall at birth or when his parent succeeds to the throne, but may not sell assets for personal benefit and has limited rights and income as a minor. If the monarch has no male children, the rights and responsibilities of the duchy belong to The Crown and there is no duke. The current duke is Charles, Prince of Wales.