Private secretary to Nugent Buckingham, main political confidant of the first Duke and a Grenvillite MP. 

The Fremantle family were from Aston Abbots, Buckinghamshire. William was brother of Thomas. See family tree. 

The Fremantle's benefited greatly from the Grenville largesse and supported the family strongly. This was especially true of William Henry Fremantle (1766–1850).

• Born 28 December 1766; youngest son of John Fremantle of Aston Abbots 
• Died 21 October 1850 at Holly Grove, Windsor Park

William joined the army and attained the rank of captain of infantry. He was on the staff of the Duke of Wellington. He served in Ireland in 1782 & 1787, during the periods when Nugent Buckingham was Lord Lieutenant. There he purchased the 58th troop of Yeomanry cavalry at a low price. This he sold at an inflated price in 1789 when he quit the service.

Appointed Deputy Teller of the Exchequer, probably in February 1792 (BRO D/FR/46/8/1). The Tellership was a highly profitable sinecure position held by Nugent Buckingham.

Other positions held:

• Lord Lieutenant of Ireland in London
• 1789–1800: Joint Solicitor in Great Britain for Irish affairs
• 1806: appointed Joint Secretary to Treasury in Grenville and Grey's administration Grenville's 'Ministry of All the Talents' at Nugent Buckingham’s instigation; quitting with Grenville on 25 March 1807
• 1821: appointed to Privy Council
• 1821: appointed to Board of Control
• 1822-1826: a Commissioner of the India Board 
• 1826: (1 May) Treasureship of the Household; retired on death of William IV in 1837
• 1827: knighted
• 1830: Deputy Ranger of Windsor Great Park until his death.

Knighted with the Grand Cross of the Royal Guelphic Order of Hanover by George IV (1826?).

In Parliament Fremantle was a major influence in the Grenvillite group:

• 1806: MP for Harwich
• 1807: Elected MP for Saltash but unseated by an election petition
• 1808 to 1812: MP for Kirkwall, Orkney Islands ('The Wick Burghs') in Lady Stafford’s interest
• 1812 to 1827: MP for Buckingham; resigned in 1827 at Richard Temple’s request.

A member of Brooks's Club. 

From 1825–27, Fremantle did not follow Richard Temple’s political line. However, he resigned from Buckingham when Buckingham opposed Canning’s ministry.

Fremantle married an heiress, Selina Hervey, on 18 September 1797, or a day or so before (BRO D-FR/46/10/1). She was 13 years his senior. Selina's maiden name was Elwell and she had previously been married to Sir Felton Hervey, who died in 1785. She settled on Fremantle £6,000 and her London House in Queen Street. This marriage gave him access to the court circle around George III, and he remained an astute courtier during George IV and Victoria. She died in 1841.

In the late 1790s, Fremantle and his wife purchased an house in Englefield Green, Surrey near Windsor. He later lived at Holly Grove, a house built  in 1752  and purchased by the Crown in 1829 to become the official residence of the Deputy Rangers. 

Obituaries 

• The Times 
• Morning Post.

Sources

Sack; obituaries (see above); DNB.