George Spencer, 4th Duke of Marlborough

His Grace The Duke of Marlborough KG PC FRS
Lord Privy Seal
In office 1763–1765
Monarch	George III
Prime Minister	George Grenville
Preceded by	The Duke of Bedford
Succeeded by	The Duke of Newcastle
Lord Chamberlain
In office 1762–1763
Monarch	George III
Prime Minister	The Earl of Bute
Preceded by	The Duke of Devonshire
Succeeded by	The Earl Gower
Personal details
Born	(1739-01-26)26 January 1739
Died	29 January 1817(1817-01-29) (aged 78) Blenheim Palace, Woodstock, Oxfordshire United Kingdom
Nationality	United Kingdom
Spouse	Lady Caroline Russell
Children	Caroline Ellis, Viscountess Clifden Lady Elizabeth Spencer George Spencer-Churchill, 5th Duke of Marlborough Lady Charlotte Nares Lord Henry John Spencer Anne Ashley-Cooper, Countess of Shaftesbury Lady Amelia Pytches Boyce Francis Spencer, 1st Baron Churchill
Parents	Charles Spencer, 3rd Duke of Marlborough Hon. Elizabeth Trevor
Military service
Allegiance	Great Britain (1755–1801)  United Kingdom (1801–1817)
Branch/service	British Army
Years of service	1755–1760
Rank	Captain
Unit	Coldstream Guards (1755) 20th Regiment of Foot (1756–1760)

George Spencer, 4th Duke of Marlborough, KG, PC, FRS (26 January 1739 – 29 January 1817), styled Marquess of Blandford until 1758, was a British courtier, nobleman, and politician from the Spencer family. He served as Lord Chamberlain between 1762 and 1763 and as Lord Privy Seal between 1763 and 1765. He is the great-great-great grandfather of Sir Winston Churchill.