Earl of Salisbury children: to his son Edward in 1485 until his execution for treason in 1499, and to Edward's sister, Margaret Pole, Countess of Salisbury, in 1513 until she was also executed, and the title again forfeited, in 1539. In 1605 the title was given to Robert Cecil, 1st Earl of Salisbury, a close advisor to James I. Cecil was a son of Queen Elizabeth I's chief advisor, William Cecil, 1st Baron Burghley. For information on this creation, see the Marquess of Salisbury. Some sources call Edward Plantagenet, 17th Earl of Warwick (1475–1499) also Earl of Salisbury, but "there is no reason
Edward Seymour, 1st Earl of Hertford to rely on Sir John Thynne for some financial support. Under Queen Mary he was "restored in blood", but was not given back his title; Queen Elizabeth I created him Earl of Hertford, in the earldom's second creation, in 1559. Between April and May 1605 following the Treaty of London (1604) he was sent on an Embassy by King James I to Albert VII, Archduke of Austria, sovereign of the Spanish Netherlands between 1598 and 1621, at Brussels, to receive his oath of peace. His first wife, Lady Catherine Grey, was a potential claimant to Elizabeth's throne, and law established