 George plotted against Edward IV, and was attainted and executed for treason; his lands and titles were forfeited.Edward IV died when Margaret was ten, and her uncle Richard, Duke of Gloucester, declared that Edward's marriage was invalid, his children illegitimate, and that Margaret and her brother Edward were debarred from the throne by their father's attainder.Married to Anne Neville, younger sister to Margaret's mother Isabel, Richard assumed the throne himself as Richard III.