Earl Grandison

Viscount Grandison of Limerick, is a title in the Peerage of Ireland. It was created in 1620 for Sir Oliver St John, the Lord Deputy of Ireland. He was the descendant and namesake of Oliver St John, whose elder brother Sir John St John was the ancestor of the Barons St John of Bletso and the Earls of Bolingbroke. Moreover, St John's nephew Sir John St John, 1st Baronet, of Lydiard Tregoze, was the ancestor of the Viscounts Bolingbroke and the Viscounts St John.

At the time of its creation in 1620, the Grandison viscountcy was given special remainder to the male issue of his niece Barbara Villiers. She was the wife of Sir Edward Villiers, the elder half-brother of George Villiers, 1st Duke of Buckingham, Christopher Villiers, 1st Earl of Anglesey and John Villiers, 1st Viscount Purbeck.

In 1626 the 1st Viscount Grandison was also created Baron Tregoz in the Peerage of England, with normal remainder to the heirs male of his body. On his death in 1630 the barony of Tregoz became extinct as he left no male heirs. He was succeeded in the viscountcy according to the special remainder by William Villiers, the eldest son of Barbara and Sir Edward Villiers. William Villiers, 2nd Viscount Grandison (1614–1643) was a supporter of King Charles I and died of wounds received at the Battle of Bristol in 1643. His daughter the Hon. Barbara Villiers, became the mistress of King Charles II and was created Duchess of Cleveland in 1670.

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