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 was a reference to speeches made in Parliament condemning the murder of the princes, which suggested that Richard's guilt had become common knowledge, or at least common wisdom. The plausibility of Henry Stafford, 2nd Duke of Buckingham, Richard's right-hand man, as a suspect depends on the princes having already been dead by the time Stafford was executed in November 1483. It has been suggested that Buckingham had several potential motives. As a descendant of Edward III, through John of Gaunt, 1st Duke of Lancaster and Thomas of Woodstock, 1st Duke of Gloucester on his father's side, as well as through