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the legitimacy of his wife or her claim as heiress of Edward IV called into question, prior to the marriage he had repealed the "Titulus Regius" which had previously declared the princes (and Elizabeth) illegitimate.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 among others. It has also been suggested that one or both princes may have escaped assassination. In 1487, Lambert Simnel initially claimed to be Richard, Duke of York, but later claimed to be Edward Plantagenet, 17th Earl of Warwick. From 1491 until his capture in 1497, Perkin Warbeck claimed to be Richard, Duke of York, having supposedly escaped to Flanders. Warbeck's claim was supported by some contemporaries (including the aunt of the disappeared princes, Margaret of York). In 1674, workmen at the Tower dug up a wooden box containing two small human skeletons. The bones were found in a box