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the legitimacy of his wife or her claim as heiress of Edward IV called into question, prior to the marriage he had repealed the "Titulus Regius" which had previously declared the princes (and Elizabeth) illegitimate.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 his brother from the Tower before it was too late", but that, when the Duke of Buckingham became involved, it shifted to support of Henry Tudor because "Buckingham almost certainly knew that the princes in the Tower were dead." Alison Weir proposes 3 September 1483 as a potential date; however, Weir's work has been criticised for "arriving at a conclusion that depends more on her own imagination than on the uncertain evidence she has so misleadingly presented." Sir Clements Markham suggests the princes may have been alive as late as July 1484, pointing to the regulations issued by Richard III's