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the legitimacy of his wife or her claim as heiress of Edward IV called into question, prior to the marriage he had repealed the "Titulus Regius" which had previously declared the princes (and Elizabeth) illegitimate.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 was a reference to speeches made in Parliament condemning the murder of the princes, which suggested that Richard's guilt had become common knowledge, or at least common wisdom. The plausibility of Henry Stafford, 2nd Duke of Buckingham, Richard's right-hand man, as a suspect depends on the princes having already been dead by the time Stafford was executed in November 1483. It has been suggested that Buckingham had several potential motives. As a descendant of Edward III, through John of Gaunt, 1st Duke of Lancaster and Thomas of Woodstock, 1st Duke of Gloucester on his father's side, as well as through