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 his brother from the Tower before it was too late", but that, when the Duke of Buckingham became involved, it shifted to support of Henry Tudor because "Buckingham almost certainly knew that the princes in the Tower were dead." Alison Weir proposes 3 September 1483 as a potential date; however, Weir's work has been criticised for "arriving at a conclusion that depends more on her own imagination than on the uncertain evidence she has so misleadingly presented." Sir Clements Markham suggests the princes may have been alive as late as July 1484, pointing to the regulations issued by Richard III's