Henry Unwin Addington

Henry Unwin Addington (24 March 1790 – 6 March 1870) was a British diplomat and civil servant. He was born at Blounts Court, the second son of John Hiley Addington and Mary Unwin. His paternal uncle was Henry Addington, 1st Viscount Sidmouth. His maternal grandfather was Henry Unwin. Addington received his education at Winchester School and commenced his career at the Foreign Office in 1807.

In 1809, Addington was assigned to the diplomatic mission in Sicily under William Amherst, 1st Earl Amherst. He participated in negotiations between Spain and its colonies in 1812. The following year, he was transferred to Berlin in April 1813 and then to Stockholm in September of the same year.

In 1814, Addington was appointed Secretary of Legation in Switzerland, a position he held until 1818. He later served as Secretary of Legation in Copenhagen in 1821. In 1822, he became chargé d'affaires in Washington, D.C. In 1826, he was promoted to plenipotentiary in London to conduct negotiations with the United States. Two years later, in 1828, he was appointed Minister Plenipotentiary to the German Confederation in Frankfurt am Main.

In 1829, Addington was appointed Envoy Extraordinary to Spain. He returned to England in 1833. In 1842, he became Permanent Under-Secretary of State for Foreign Affairs, a senior position within the Foreign Office. He held this role until 1854, when he retired from public service. Upon retirement, he was sworn into the Privy Council of the United Kingdom.

On 17 November 1836, Addington married Eleanor Anne Estcourt, the eldest daughter of Thomas Grimston Bucknall Estcourt, at St George's, Hanover Square.

References and further reading about Addington's diplomatic activities, particularly his time in Germany in 1813–1814 and 1828–1829, are documented by Oliver Werner in the publication "Privater Eindruck und öffentliche Politik. Der britische Diplomat Henry Unwin Addington in Deutschland, 1813/14 und 1828/29," included in the collection edited by Uwe Ziegler and Horst Carl titled "In unserer Liebe nicht glücklich," published in Göttingen by Vandenhoeck & Ruprecht in 2014, pages 143–158.