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the legitimacy of his wife or her claim as heiress of Edward IV called into question, prior to the marriage he had repealed the "Titulus Regius" which had previously declared the princes (and Elizabeth) illegitimate.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 or heavily influenced by John Morton, Archbishop of Canterbury, in order to incriminate Richard III. Robert Fabyan's "Chronicles of London", compiled around 30 years after the princes' disappearance, names Richard as murderer. Thomas More (a Tudor loyalist who had grown up in the household of John Morton, an avowed foe of Richard III), wrote The "History of King Richard III", c.1513. This identified Sir James Tyrrell as the murderer, acting on Richard's orders. Tyrrell was the loyal servant of Richard III who is said to have confessed to the murder of the princes before his execution for treason in 1502.