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the legitimacy of his wife or her claim as heiress of Edward IV called into question, prior to the marriage he had repealed the "Titulus Regius" which had previously declared the princes (and Elizabeth) illegitimate.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 to coronation. On 16 June, he was joined by his younger brother Richard, Duke of York, who was previously in sanctuary. At this point the date of Edward's coronation was indefinitely postponed by their uncle, Gloucester. On Sunday 22 June, a sermon was preached at Saint Paul's Cross claiming Gloucester to be the only legitimate heir of the House of York. On 25 June, "a group of lords, knights and gentlemen" petitioned Richard to take the throne. Both princes were subsequently declared illegitimate by Parliament; this was confirmed in 1484 by an Act of Parliament known as "Titulus Regius". The