Lady Joan Stafford (c.1442-c.1485) Parents Humphrey Stafford, 1st Duke of Buckingham Anne Neville, Duchess of Buckingham Children Charles Knyvett, of Hamerton Siblings Lady Anne Stafford Humphrey Stafford, Earl of Stafford John Stafford, 1st Earl of Wiltshire Lady Catherine Stafford Sir Henry Stafford Partners William Beaumont, 2nd Viscount Beaumont Sir William Knyvett