According to the Dictionary of Dates (my copy was published in 1881),
"the Foreign Office was established at the re-arrangement of the duties of secretaries of state in 1782. It has the exclusive charge of British interests and subjects in foreign countries. The secretary for foreign affairs negotiates treaties, selects ambassadors, consuls, &c, for foreign countries, and grants passports".
Many Foreign Secretaries became well-known, especially during times of war. Some of them were more significant and more important for British history than the Prime Ministers who had chosen them, while some Prime Ministers had been Foreign Secretary earlier in their career. Along with, or even ahead of the Chancellor of the Exchequer, the Foreign Secretary is the most important man behind the Prime Minister.
On some occasions, the tasks of the Foreign Secretary, the Colonial Secretary and even the War Secretary, were so similar, that the ones who held these Offices had arguments who was responsible for certain affairs. Most notably, these "differences" led to a duel between George Canning and Lord Castlereagh, Foreign and War Secretary, respectively, in 1809, in which Canning was slightly wounded.
In this chapter, I have listed the Foreign Secretaries since 1782. There´s only one missing in my collection (I have still to include some scans of the more recent secretaries). Some Foreign Secretaries appear in the "Prime Minister"-sections already. They are just named here, but I didn´t give any further description or signature here. If you haven´t done already, please have a look for them in the "Prime Minister"-section.
Charles James Fox (1749-1806) was the first one who was appointed "Foreign Secretary" by the Marquess of Rockingham on 27th March 1782. After Rockingham died in Office, Fox was also available for the Duke of Portland in April 1783. The Duke, however, was only leading a formation that was called "Fox-North"-coalition, with Fox and the former PM Lord North as heads of Whig- and Tory-fractions. This government ended the same year. In February 1806, during the last months of his life, Fox returned as Foreign Secretary under Lord Grenville.
The 1st Viscount Sydney (Thomas Townshend, 1733-1800), Foreign Secretary 13th July 1782- 2nd April 1783 under Rockingham, 23rd Dec. 1783-May 1791 under Pitt, the Younger.
The 2nd Earl Temple (George Grenville, later the 1st Marquess of Buckingham, 1753-1813), Foreign Secretary Dec. 19-23, 1783 under Pitt, the Younger.
Lord Grenville (William Wyndham Grenville,1759-1834), Foreign Secretary 8th June 1791-Feb. 1801 under Pitt, the Younger (he became Prime Minister himself 1806-07).
Robert B. Jenkinson (1770-1828), Foreign Secretary 20th Feb. 1801-May 1804 under Addington, and 1809 (he became Prime Minister himself as the 2nd Earl of Liverpool 1812-27).
1st Earl of Harrowby (Dudley Ryder, 1762-1847), Foreign Secretary 14th May 1804-Jan. 1805 under Pitt, the Younger. Despite what his short time in this important office may suggest, he had a very long political and diplomatic career.
1st Earl of Mulgrave (Henry Phipps, 1755-1831), Foreign Secretary 11th Jan. 1805-Feb. 1806 under Pitt, the Younger.
The Viscount Howick (Charles Grey, 1764-1845), Foreign Secretary 24th Sept. 1806-March 1807 under Lord Grenville (he became Prime Minister himself as the 2nd Earl Grey 1830-34).
George Canning (1770-1827), Foreign Secretary 25th March 1807-Sept. 1809 under Portland, and 16th Sept. 1822- April 1827 under Liverpool (he became Prime Minister himself in 1827).
The 3rd Earl Bathurst (Henry Bathurst, 1762-1834), Foreign Secretary 11th Oct. 1809-Dec. 1809 under Portland; later, he was Secretary for War and Colonies from 1812-27. Bathurst was given much credit for the conduct of the "Peninsular War" in his early years as War Secretary.
The Marquess of Wellesley (Richard Wellesley, 1760-1842, brother of the Duke of Wellington), Foreign Secretary 6th Dec. 1809- March 1812 under Perceval). Before that, he was Governor-General of India 1797-1805; during this time, British rule in India became supreme. Other posts, a.o., were British ambassador in Madrid and Lord Lieutenant of Ireland (1821 and 1833).
The Viscount Castlereagh (Robert Stewart, 1769-1822), Foreign Secretary 4th March 1812- 12th August 1822 under the Earl of Liverpool. Lord Castlereagh ranges among the most significant political figures in Great Britain who never became Prime Minister. As War- (1807-09) and Foreign Secretary he had to deal with the Wars against Napoleon´s France, later negotiating Peace-Treaties and securing Peace for Europe for decades. He was so unpopular, however, that a shout of joy was given as his coffin was carried into Westminster Abbey. The lack of public popularity in his last years depressed him and led to his suicide by cutting his throat with a pen-knife.
The Earl of Dudley (John William Ward, 1781-1833), Foreign Secretary 30th April 1827 - June 1828 under Canning and the Viscount Goderich.
The 4th Earl of Aberdeen (George Hamilton Gordon, 1784-1860), Foreign Secretary 2nd June 1828-Nov. 1830 under Wellington, 2nd Sept. 1841-July 1846 under Peel (he became Prime Minister himself 1852-55).
Lord Palmerston (Henry John Temple, 1784-1865), Foreign Secretary 22nd Nov. 1830-Nov. 1834 under Grey, 18th April 1835- 2nd Sept. 1841 under Melbourne, 6th July 1846- Dec. 1851 under Russell (he became Prime Minister himself 1855-58 and 1859-65).
The Duke of Wellington (Arthur Wellesley, 1769-1852), Foreign Secretary 15th Nov. 1834- April 1835 under Peel (he had been Prime Minister himself 1828-30).
The 2nd Earl Granville (George Leveson-Gower, 1815-91), Foreign Secretary 26th Dec.1851- Feb. 1852 under Russell, 6th July 1870-Feb. 1874 and 28th April 1880- June 1885 under Gladstone.
The 3rd Earl of Malmesbury (James Howard Harris, 1807-89), Foreign Secretary 27th Feb.-Dec.1852 and 26th Feb. 1858-June 1859 under Derby.
Lord John Russell (1792-1878), Foreign Secretary 28th Dec. 1852-Feb. 1853 under Aberdeen, 18th June 1859-Nov. 1865 under Palmerston (he had been Prime Minister himself 1846-52 and 1865-66).
The 4th Earl of Clarendon (George William Frederick Villiers, 1800-70), Foreign Secretary 21st Feb. 1853-Feb. 1858 under Aberdeen and Palmerston, 3rd Nov. 1865-July 1866 under Russell and 9th Dec. 1868- July 1870 under Gladstone.
Lord Stanley (Edward Stanley, 1826-93), Foreign Secretary 6th July 1866-Dec. 1868 under his father, the 14th Earl of Derby, and Disraeli, and once more 21st Feb. 1874- April 1878 under Disraeli, this time after he had inherited the title. That´s why here are the two signatures, one as Lord Stanley, the other one from later days as (15th Earl of) Derby.
The 3rd Marquess of Salisbury (Robert Gascoyne-Cecil, 1830-1903), Foreign Secretary 2nd April 1878-April 1880 under Disraeli and Gladstone, as well as 24th June 1885- Feb. 1886, 14th Jan. 1887-92 and 1895-1900 when he himself was Prime Minister.
The 5th Earl of Rosebery (Archibald Primrose, 1847-1929), Foreign Secretary 6th Feb.-Aug. 1886 and 1892-94 under Gladstone (he became Prime Minister himself 1894-95).
The 1st Earl of Iddesleigh (Stafford Henry Northcote, 1818-87), Foreign Secretary 3rd Aug.1886-1887 under Salisbury. He had been Chancellor of the Exchequer under Disraeli 1774-80.
The 1st Earl of Kimberley (John Wodehouse, 1826-1902), Foreign Secretary 1894-95 under Rosebery.
The 5th Marquess of Lansdowne (Henry Charles Keith Petty-Fitzmaurice, 1845-1927), Foreign Secretary 1900-05 under Salisbury and Balfour.
Edward Grey (1862-1933, later Viscount Grey of Falladon), Foreign Secretary 1905-16 under Campbell-Bannerman and Asquith. He was a nephew of the 2nd Earl Grey. An ornithologist and fisherman in private life, he remained in politics from a sense of duty, not of choice. Nevertheless, no one before or after him was in this office for such a long continous time.
Arthur James Balfour (1848-1930), Foreign Secretary 1916-19 under Lloyd George (he had been Prime Minister himself 1902-05).
The Earl Curzon of Kedleston (George Curzon, 1859-1925, later Marquess of Curzon), Foreign Secretary 1919-24 under Lloyd George, Bonar Law and Baldwin. He was another significant politician who didn´t become Prime Minister. In his political career, he had started as a secretary of the 3rd Marquess of Salisbury, who helped him in later years. Among the posts he held under Salisbury were "Under Secretary" for India and Foreign Affairs, and most notably Vice-Roy of India 1898-1905.
J. Ramsey MacDonald (1866-1937), Foreign Secretary 1924, while he served as Prime Minister as well (he was Prime Minister twice more 1929-31 and 1931-35).
Austen Chamberlain (1863-1937), Foreign Secretary 1924-29 under Baldwin. He comes from a political important family: His father Joseph was Secretary for the Colonies (1895-1903), his brother Neville became Prime Minister (1938-40). Austen Chamberlain was honoured with the Peace Nobel-Price in 1925.
Arthur Henderson (1863-1935, left), Foreign Secretary 1929-31 under MacDonald; in 1934, he received the Nobel Peace Price.
The 1st Marquess of Reading (Rufus Daniel Isaacs, 1860-1935, right), Foreign Secretary 1931 under MacDonald.
John Simon (1873-1954, later 1st Viscount Simon), Foreign Secretary 1931-35 under MacDonald. He held many important Offices during his career, among them Home Secretary (1915-16 and 1935-37), Chancellor of the Exchequer (1937-40) and Lord Chancellor (1940-45). The signature on the left, by the way, is on an official document which is also signed by King George V.
Sir Samuel Hoare (Samuel John Gurney Hoare, 1880-1959, later the 1st Viscount Templewood of Chelsea), Foreign Secretary 1935 under Baldwin.
Anthony Eden (1897-1977, later the Earl of Avon), Foreign Secretary 1935-38 under Baldwin, 1940-45 and 1951-55 under Churchill (he became Prime Minister himself 1955-57).
The 1st Earl of Halifax (Edward Wood, 1881-1959), Foreign Secretary 1938-40 under Chamberlain.
Ernest Bevin (1881-1951), Foreign Secretary August 1945- March 1951 under Attlee. He had been Secretary for Labour and National Service 1940-45 in Churchill´s War-government already. When his Labour-party colleague Attlee won the General election in 1945, King George VI advised him to give Bevin the post of Foreign Secretary. He deepened the relationship with the United States and supported the creation of the NATO (North Atlantic Treaty Organization). The signature on the right is on an official document which is also signed by King George VI.
Herbert Morrison (1888-1965, later Lord Morrison of Lambeth), Foreign Secretary March - October 1951 under Attlee.
Harold Macmillan (1894-1986, the 1st Earl of Stockton later), Foreign Secretary 1955 under Eden (he became Prime Minister himself 1957-63).
Selwyn Lloyd (1904-78, later Lord Selwyn-Lloyd), Foreign Secretary 1955-60 under Eden and Macmillan (and Chancellor of the Exchequer 1960-62). See signed photo on the right, click on it to see a more detailed scan of the signature.
Alec Douglas Home (1903-95, Lord Home), Foreign Secretary 1960-63 under Macmillan, 1970-74 under Heath (he was Prime Minister himself 1963-64).
R.A. Butler (1902-82, later Lord Butler of Saffron Walden), Foreign Secretary 1963-64. He was one of the few politicians who held the important offices of Chancellor of the Exchequer, foreign- and home-secretary, under Churchill, Macmillan and Home. He was in charge of the government during PM Eden´s illness.
Patrick Gordon Walker (1907-80, later Lord Gordon-Walker), Foreign Secretary 1964-65 under Wilson.
Michael Stewart (1906-90, later Lord Stewart), Foreign Secretary 1965-66 and 1968-70 under Wilson.
George Brown (1914-85, later Lord George-Brown), Foreign Secretary 1966-68 under Wilson.
James Callaghan (*1912, later Lord Callaghan), Foreign Secretary 1974-76 under Wilson (he became Prime Minister himself 1976-79).
Anthony (C.A.R.) Crosland (1918-77) Foreign Secretary 1976-77 under Callaghan (right).
David Owen (*1938, later Lord Owen), Foreign Secretary 1977-79 under Callaghan.
Lord Carrington (Peter Carrington, *1919), Foreign Secretary 1979-82 under Thatcher.
Francis Pym (*1922, later Lord Pym), Foreign Secretary 1982-83 under Thatcher.
Geoffrey Howe (*1926, later Lord Howe), Foreign Secretary 1983-89 under Thatcher.
John Major (*1943), Foreign Secretary 1989 under Thatcher (he became Prime Minister himself 1990-97).
Douglas Hurd (*1930, later Lord Hurd), Foreign Secretary 1989-95 under Thatcher and Major.
Malcolm Rifkind (*1946), Foreign Secretary 1995-97 under Major.
Robin Cook (1946-2005), Foreign Secretary 1997-2001 under Blair, he was appointed Leader of the House of Commons after the 2001 election (a post he held until 2003, resigning over the Iraq-war).
Jack Straw (*1946), Foreign Secretary 2001-06 under Blair (right). He was Home-Secretary during Blair´s first term (1997-2001), then changed to the Foreign Affairs. Straw (right) became the centre of public interest together with Blair after the 11th September 2001, when Great Britain became the most important partner of the United States in their fight against terrorism and the following wars against Afghanistan and the Iraq. From May 2006 until June 2007, he was Leader of the House of Commons, after which he was appointed Lord Chancellor.
Margaret M. Beckett (*1943), Foreign Secretary 2006-7. She had been Leader of the House of Commons 1998-2001, among other governmental posts (she was the only one left with experiences in Wilson´s and Callaghan´s Labour governments). Her first immediate challenges were, a.o., the Iran atomic affair and the Israel-Lebanon conflict. She had to go when Tony Blair retired.
David Miliband (*1965), Foreign Secretary 2007-. One of the heads responsible for Tony Blair's "New Labour"-policy on the occasion of the general election in 1997 and his most important advisor afterwards, he had held several posts in the government since 2001, until he was appointed by new Prime Minister Gordon Brown on 28th June 2007.