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the legitimacy of his wife or her claim as heiress of Edward IV called into question, prior to the marriage he had repealed the "Titulus Regius" which had previously declared the princes (and Elizabeth) illegitimate.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 goal. This theory formed the basis of Sharon Penman's historical novel, "The Sunne in Splendour". Henry VII (Henry Tudor), following his seizure of the crown, executed some of the rival claimants to the throne. One who was either executed or died in captivity was John of Gloucester, illegitimate son of Richard III. Henry was out of the country between the princes' disappearance and August 1485, thus his only opportunity to murder them would have been after his accession in 1485. Pollard suggests Henry (or those acting on his orders) is "the only plausible alternative to Richard III." The year after