William Thomas Horner Fox-Strangways, 4th Earl of Ilchester FRS (7 May 1795 – 10 January 1865), styled The Honourable William Fox-Strangways until 1858, was a British diplomat, Whig politician and art collector. He served as Under-Secretary of State for Foreign Affairs under Lord Melbourne from 1835 to 1840 and was Envoy Extraordinary and Minister Plenipotentiary to the German Confederation from 1840 to 1849. Background and education Fox-Strangways was the son of Henry Thomas Fox-Strangways, 2nd Earl of Ilchester, and his second wife Maria Digby, daughter of William Digby. Henry Fox-Strangways, 3rd Earl of Ilchester, was his elder half-brother and John Fox-Strangways his younger brother. He was educated at Christ Church, Oxford, taking a BA in 1816 and an MA in 1820. Political and diplomatical career Fox-Strangways served as an attaché at the British embassies in St Petersburg, Constantinople, Naples and The Hague, as Secretary of Legation in Florence and Naples and as Secretary of Embassy in Vienna. In 1835 he was appointed Under-Secretary of State for Foreign Affairs in the Whig administration of Lord Melbourne, a post he held until 1840 (however, he was not a Member of Parliament during this time). The latter year he was appointed Envoy Extraordinary and Minister Plenipotentiary to the German Confederation, which he remained until 1849. In 1858 he succeeded his half-brother as fourth Earl of Ilchester and entered the House of Lords. He was elected a Fellow of the Royal Society in March 1821. Geological work Fox-Strangways was interested in geology and was elected as a Member of the Geological Society in 1815, serving on the Council 1820-1821. When he was attaché at the British Embassy in St Petersburg Fox-Strangways wrote ‘Geological sketch of the environs of Petersburg’ published in the Transactions of the Geological Society of London in 1821 (read on 16 April 1819), which includes a coloured geological map of the St Petersburg region, distinguishing four rock types, as well as some cross-sections and scenic views along the river banks. His work was expanded in a paper read to the Geological Society in 1821 published as 'An Outline of the Geology of Russia', which includes a 'Sketch to serve as a basis for a Geological Map of European Russia Coloured to show the connections of its the Strata with this of the Surrounding Countries'. The map is mineralogical, that is essentially charting lithological types, depicting 24 different types, labelled A to