Princes in the Tower becoming king, Henry married the princes' eldest sister, Elizabeth of York, to reinforce his claim to the throne. Not wanting the legitimacy of his wife or her claim as heiress of Edward IV called into question, prior to the marriage he had repealed the "Titulus Regius" which had previously declared the princes (and Elizabeth) illegitimate. Markham suggests the princes were executed under Henry's orders between 16 June and 16 July 1486, claiming that it was only after this date that orders went out to circulate the story that Richard had killed the princes, and that the princes' mother, Elizabeth Woodville,
Princes in the Tower were under guard in the Tower of London, which was controlled by his men, and access to them was strictly limited by his instructions. He could therefore have dispatched one of his retainers to murder the princes on his behalf, but it is unlikely they could have been murdered without his knowledge. This is the version put forward by More and Polydore Vergil, who both name James Tyrrell as the murderer. Tyrrell was an English knight who fought for the House of York on many occasions. Tyrrell was arrested by Henry VII's forces in 1502 for supporting another Yorkist claimant