succeeded as eighth Baron Saye and Sele in 1613 and was created first Viscount in 1624
He invested in the Puritan colonial ventures on Providence Island in the West Indies and at Saybrook in New England.
After the Second Civil War in 1648, he pleaded with the King to accept the Treaty of Newport, correctly foreseeing that the alternative to an agreement was rule by the Army and the destruction of both the monarchy and the peerage.
Disheartened by the regicide in 1649, Lord Saye retired from public life. He spent much of his time during the Commonwealth and Protectorate years on Lundy Island in the Bristol Channel, which he owned.
He accepted the Restoration in 1660 and was appointed a privy councillor to King Charles II, who was anxious to gain the support of former opponents of the Crown.
via BCW Project
On the death of his father Richard, William inherited the title of Baron of Saye and Sele.
On 7 July in the twenty second year of the reign of James I, William was created Viscount of Saye and Sele.
His eldest son, James succeeded his father as Baron and Viscount of Saye and Sele and died in 1673 without male issue, leaving two daughters Elizabeth and Frances. The barony of Saye and Sele therefore went into abeyance until 1781, when Lord Saye and Sele assumed his seat in the House of Lords on 29 June.
William the son of Nathaniel, the second son of the first Viscount of Saye and Sele succeeded as third Viscount of Saye and Sele, and took his seat on 13 April 1675.
His son Nathaniel succeeded as fourth Viscount of Saye and Sele in 1699 and died in 1709, without male issue,
Lawrence Fiennes, son and heir of John Fiennes the third son of the first Viscount of Saye and Sele succeeded as fifth Viscount of Saye and Sele and died without male issue in 1742.
Richard Fiennes, the grandson and heir of Richard the fourth son of the first Viscount of Saye and Sele succeeded as sixth Viscount of Saye and Sele and died without male issue in 1781.
via Historical Dictionary of Stuart England, 1603-1689 page 191