This thesis aims to examine Richmond's life in the context of his role as a magnate, a courtier, and the king's only son. As a much neglected subject this includes a good deal of biographical material, in order to present the duke within the context in which he lived. This also allows a re-assessment of his part in the succession crisis, with particular reference to the significance of his elevation in 1525, and the speculation regarding the king's intentions, as represented in the Succession Act of 1536. An examination of his responsibilities, not least as Lord Lieutenant in the north, of Ireland and as Lord Admiral, queries how far his extreme youth and his illegitimacy inhibited or facilitated the role Henry VIII wished him to fulfil. In tandem with this, a special study of the duke as a landlord looks at the relationship between the authority bestowed upon Richmond and the actual freedom of action allowed to the child. A view of his political importance, in matters such as marriage alliances and diplomacy, is considered alongside an appraisal of the personal standing of the duke, both in England and abroad. In order to provide a complete picture of Richmond's circumstances, there is also an account of the fortunes of his maternal relations, the Blounts of Kinlet, tracing their wealth and descent, and in particular those connections and alliances which assisted their daughter's acceptance at court. An analysis of Elizabeth Blount's relationship with Henry VIII leads into a consideration of how her royal liaison affected her life. In discussing the overall legacy left by Richmond's demise, the right and title of his widow, Mary Richmond, to her agreed jointure, and her subsequent fortunes, are weighed against the priorities of the king.