During Edward's reign, his brother Richard, Duke of Gloucester had risen to become the most powerful magnate in the north of England, particularly in the city of York where his popularity was high. Prior to his death, the king had named Richard as Lord Protector to act as regent to his twelve-year-old son, Edward. Acting as Lord Protector, Richard repeatedly stalled the coronation of Edward V, despite the urging of the king's councillors, who wished to avoid another protectorate. On 22 June, the selected date for Edward's coronation, a sermon was preached outside St. Paul's Cathedral declaring Richard the rightful king, a post which the citizenry petitioned Richard to accept. Richard accepted four days later, and was crowned at Westminster Abbey on 6 July 1483. The fate of the two princes following their disappearance remains a mystery to this day, however, the most widely accepted explanation is that they were murdered on the orders of Richard III.