John Alexander Thynne, 4th Marquess of Bath (March 1, 1831–April 20, 1896) was the son of Henry Thynne, 3rd Marquess of Bath.

The Marquess of Bath, by Carlo Pellegrini, 1874.

Lord Bath was educated at Eton College and Christ Church, Oxford. He held the office of Envoy Extraordinary for the coronation of King Pedro V of Portugal on 27 May 1858, and Envoy Extraordinary for the coronation of the Emperor Franz Joseph I as King of Hungary on 25 July 1867.

He was a devout Anglo-Catholic and a determined opponent of the Public Worship Regulation Act 1874 which sought to suppress Ritualism in the Church of England.

From 1874 to 1893, he was a trustee of the National Portrait Gallery and a trustee of the British Museum in 1883. He was both Chairman of Wiltshire County Council and Lord Lieutenant of Wiltshire between 1889 and 1896.

He married Frances Isabella Catherine Vesey, daughter of Thomas Vesey, 3rd Viscount de Vesci, on 20 August 1861. They had six children:

• Sir Thomas Henry Thynne, 5th Marquess of Bath (1862–1946)
• Lady Alice Emma Thynne (c. 1863–1942), married Sir Michael Shaw-Stewart, 8th Baronet.
• Katherine Georgina Louisa Thynne (c. 1865–1933), married Evelyn Baring, 1st Earl of Cromer and had issue.
• Lord John Boteville Thynne (1867–1887), died young and unmarried.
• Lady Beatrice Thynne (1867–1941), died unmarried.
• Major Lord Alexander George Thynne (1873–1918), killed in World War I, unmarried.

Lord Bath died in 1896, aged 65 in Italy and was buried at Longbridge Deverill, Wiltshire.

[edit] Titles

• John Alexander Thynne, Lord Thynne 1831–1837
• John Alexander Thynne, Viscount Weymouth 1837
• John Alexander Thynne, Marquess of Bath 1837–1896