Princes in the Tower act stated that Edward IV and Elizabeth Woodville's marriage was invalid because of Edward's pre-contract of marriage with Lady Eleanor Butler. Gloucester was crowned King Richard III of England on 3 July. The declaration of the boys' illegitimacy has been described by Rosemary Horrox as an ex post facto justification for Richard's accession. Dominic Mancini, an Italian friar who visited England in the 1480s and who was in London in the spring and summer of 1483, recorded that after Richard III seized the throne, Edward and his younger brother Richard were taken into the "inner apartments of the Tower" and
Princes in the Tower to speculate when or by whose hand." During the reign of Henry VII, two individuals claimed to be Richard, Duke of York, who had somehow escaped death. Lambert Simnel initially claimed to be Richard, before changing his story and claiming to be Edward Plantagenet, 17th Earl of Warwick. Perkin Warbeck later claimed to be Richard, appearing in Ireland and calling himself king Richard IV. Margaret of York, Duchess of Burgundy, formally recognised Warbeck as Richard. Margaret, Richard III's sister, an unrelenting opponent of Henry VII, had previously recognised Simnel as Warwick. Warbeck was also accepted as Richard by James IV