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the legitimacy of his wife or her claim as heiress of Edward IV called into question, prior to the marriage he had repealed the "Titulus Regius" which had previously declared the princes (and Elizabeth) illegitimate.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 it would discourage rebellion. Holinshed's Chronicles, written in the second half of the 16th century, claims that the princes were murdered by Richard III. The chronicles were one of the main sources used by William Shakespeare for his play "Richard III", which also portrays Richard as the murderer, in the sense that he commissions Tyrrell to have the boys killed. A. J. Pollard believes that the chronicle's account reflected the contemporary "standard and accepted account", but that by the time it was written "propaganda had been transformed into historical fact". It should also be noted that Thomas More wrote his