His potential claim to the throne following the deposition of his cousin Edward V in 1483 was overlooked because of the argument that the attainder of his father barred Warwick from the succession (although that could have been reversed by an act of Parliament).

[2] In 1480,[3] Warwick was made a ward of King Edward IV's stepson, Thomas Grey, 1st Marquess of Dorset, who as his guardian had the power to decide whom he would marry.

Dominic Mancini wrote that Richard, on becoming king, "gave orders that the son of the duke of Clarence, his other brother, then a boy of ten years old, should come to the city: and commanded that the lad should be kept in confinement in the household of his wife".

He remained a prisoner until 1499, when he became involved (willingly or unwillingly) in a plot to escape with Perkin Warbeck, who had been imprisoned for falsely presenting himself as Richard III's nephew, the Duke of York.

This conclusion appears entirely based on the chronicler Edward Hall's contention that Warwick's lengthy imprisonment from a young age had left him "out of all company of men, and sight of beasts, in so much that he could not discern a goose from a capon.