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 were under guard in the Tower of London, which was controlled by his men, and access to them was strictly limited by his instructions. He could therefore have dispatched one of his retainers to murder the princes on his behalf, but it is unlikely they could have been murdered without his knowledge. This is the version put forward by More and Polydore Vergil, who both name James Tyrrell as the murderer. Tyrrell was an English knight who fought for the House of York on many occasions. Tyrrell was arrested by Henry VII's forces in 1502 for supporting another Yorkist claimant