Question: What years did ponsonby baronet serve a conservative politician before they became a prime minister

full_context: Document 1: Conservative government, 1957–1964: The Conservative government of the United Kingdom that began in 1957 and ended in 1964 consisted of three ministries: the first Macmillan ministry, second Macmillan ministry, and then the Douglas-Home ministry. They were led by Harold Macmillan and Sir Alec Douglas-Home, who were appointed respectively by Queen Elizabeth II.
Document 2: Bossom baronets: The Bossom Baronetcy, of Maidstone in the County of Kent, is a title in the Baronetage of the United Kingdom. It was created on 4 July 1953 for the architect and Conservative Member of Parliament for Maidstone, Alfred Bossom. In 1960 he was further honoured when he was created a life peer as Baron Bossom, "of Maidstone in the County of Kent". The life peerage became extinct on his death in 1965 while he was succeeded in the baronetcy by his second but only surviving son, the second holder of the baronetcy. He was a former Conservative Member of Parliament for Leominster.
Document 3: Thatcher baronets: The Thatcher baronetcy, of Scotney in the County of Kent, is a Baronetcy created for the businessman Denis Thatcher on 7 December 1990 following the resignation of his wife, Conservative Prime Minister Margaret Thatcher, that year. The current holder is Mark Thatcher, who succeeded his father in 2003.
Document 4: Neville Chamberlain: Arthur Neville Chamberlain, ( ; 18 March 1869 – 9 November 1940) was a British Conservative politician who served as Prime Minister of the United Kingdom from May 1937 to May 1940. Chamberlain is best known for his appeasement foreign policy, and in particular for his signing of the Munich Agreement in 1938, conceding the German-speaking Sudetenland region of Czechoslovakia to Germany. However, when Adolf Hitler later invaded Poland, the UK declared war on Germany on 3 September 1939, and Chamberlain led Britain through the first eight months of World War II.
Document 5: Strickland-Constable baronets: The Strickland, later Cholmley, later Strickland-Constable Baronetcy, of Boynton in the County of York, is a title in the Baronetage of England. It was created on 30 July 1641 for the politician William Strickland. He was summoned to Oliver Cromwell's House of Lords as Lord Strickland. The second Baronet sat as Member of Parliament for Beverley during the Commonwealth. The third Baronet was a politician and racehorse owner. The fourth Baronet was also a politician and served as Secretary at War from 1730 to 1735. The seventh Baronet was a barrister and Whig politician. He married Mary, daughter and heiress of Reverend Charles Constable, of Wassand. In 1865 he succeeded to the substantial estates of Nathaniel Cholmley and assumed the same year by Royal permission the surname of Cholmley in lieu of his patronymic for himself and those of his heirs male who may succeeded to the Cholmley estates. However, his son and successor, the eighth Baronet, reverted to the use of the surname of Strickland. The ninth Baronet became a Czechoslovakian citizen and did not use his title. Since the tenth Baronet succeeded to the title in 1938 the baronets have used the surname of Strickland-Constable.
Document 6: Ponsonby baronets: The Ponsonby Baronetcy, of Wootton in the County of Oxford, is a title in the Baronetage of the United Kingdom. It was created on 27 January 1956 for the Conservative politician Charles Ponsonby. He had earlier represented Sevenoaks in the House of Commons and served as Parliamentary Private Secretary to the Foreign Secretary Anthony Eden from 1941 to 1945. A member of the prominent Ponsonby family headed by the Earl of Bessborough, he was the son of the Hon. Edwin Charles William Ponsonby, fourth son of Charles Ponsonby, 2nd Baron de Mauley. As of 2010 the title is held by the second Baronet's son, the third Baronet, who succeeded in 2010. His father was Lord Lieutenant of Oxfordshire between 1980 and 1996. As a descendant of the second Baron de Mauley, he is also in remainder to this title as well as to the earldom of Bessborough.
Document 7: Boyle baronets: The Boyle Baronetcy, of Ockham in Salehurst in the County of Sussex, is a title in the Baronetage of the United Kingdom. It was created on 14 December 1904 for Edward Boyle a barrister, businessman and Conservative Member of Parliament for Taunton. His grandson, the third Baronet, was also a Conservative Member of Parliament and ultimately cabinet minister serving as Minister of Education from 1962 to 1964. He was made a life peer as Baron Boyle of Handsworth, of Salehurst in the County of Sussex, in 1970 and became Vice-Chancellor of the University of Leeds in the same year. The life peerage became extinct on his death in 1981 and he was succeeded in the baronetcy by his younger brother, the fourth Baronet. As of 2010 the title is held by the latter's eldest son, the fifth Baronet, who succeeded in 1983.
Document 8: Anthony Eden: Robert Anthony Eden, 1st Earl of Avon, (12 June 1897 – 14 January 1977) was a British Conservative politician who served three periods as Foreign Secretary and then a relatively brief term as Prime Minister of the United Kingdom from 1955 to 1957.
Document 9: Anthony Eden hat: An "Anthony Eden" hat, or simply an "Anthony Eden", was a silk-brimmed, black felt Homburg of the kind favoured in the 1930s by Anthony Eden, later 1st Earl of Avon (1897–1977). Eden was a Cabinet Minister in the British National Government, holding the offices of Lord Privy Seal from 1934–1935 and Foreign Secretary 1935 to 1938. He was later Dominions Secretary from 1939–1940, War Secretary in 1940, Foreign Secretary from 1940–1945 and 1951–1955, and Prime Minister 1955 to 1957.
Document 10: Clarissa Eden: Anne Clarissa Eden, Dowager Countess of Avon ("née" Spencer-Churchill; born 28 June 1920) is the widow of Anthony Eden, 1st Earl of Avon (1897–1977), who was British Prime Minister from 1955 to 1957. She married Eden in 1952, becoming Lady Eden in 1954 when he was made a Knight of the Garter, and then becoming Countess of Avon in 1961 on her husband's elevation to the peerage. She is also the niece of the prime minister Winston Churchill. Her memoir, sub-titled "From Churchill to Eden", was published in 2007 under the name of Clarissa Eden.
Document 11: Baron Northbourne: Baron Northbourne, of Betteshanger in the County of Kent, is a title in the Peerage of the United Kingdom. It was created in 1884 for Sir Walter James, 2nd Baronet, who had earlier represented Hull in the House of Commons as a Conservative. His son, the second Baron, sat as a Liberal Member of Parliament for Gateshead. s of 2010 the titles are held by the latter's great-grandson, the fifth Baron, who succeeded his father in 1982. Lord Northbourne is one of the ninety elected hereditary peers that were allowed to remain in the House of Lords after the passing of the House of Lords Act 1999, and sits as a cross-bencher. The James Baronetcy, of Langley Hall, in the County of Berkshire, was created in the Baronetage of Great Britain in 1791 for the first Baron's grandfather Sir Walter James, the last Warden of the Mint. Born Walter James Head, he assumed by Act of Parliament the surname of James only in 1778. His son and heir John James notably served as Minister Plenipotentiary to the Netherlands. The latter was the father of the second Baronet, who was raised to the peerage in 1884.
Document 12: Stanley Baldwin: Stanley Baldwin, 1st Earl Baldwin of Bewdley, (3 August 186714 December 1947) was a British Conservative politician who dominated the government in his country between the two world wars. Three times Prime Minister, he is the only premier to have served under three monarchs (George V, Edward VIII and George VI).
Document 13: Harold Macmillan: Maurice Harold Macmillan, 1st Earl of Stockton, {'1': ", '2': ", '3': ", '4': "} (10 February 1894 – 29 December 1986) was a British statesman of the Conservative Party who served as Prime Minister of the United Kingdom from 1957 to 1963. Nicknamed "Supermac", he was known for his pragmatism, wit and unflappability.
Document 14: Baron Derwent: Baron Derwent, of Hackness in the North Riding of the County of York, is a title in the Peerage of the United Kingdom. It was created in 1881 for the former Liberal Member of Parliament for Scarborough, Sir Harcourt Vanden-Bempde-Johnstone, 3rd Baronet. His grandson, the third Baron (who succeeded his uncle the second Baron), was an author, poet and minor diplomat. On his death in 1949 the titles passed to his younger brother, the fourth Baron. He served in the Conservative administrations of Harold Macmillan and Sir Alec Douglas-Home as Minister of State for Trade and Minister of State for Home Affairs. s of 2010 the titles are held by his son, the fifth Baron, who succeeded in 1986.
Document 15: Baron Astor of Hever: Baron Astor of Hever, of Hever Castle in the County of Kent, is a title in the Peerage of the United Kingdom. It was created in 1956 for the prominent newspaper proprietor and Conservative politician the Hon. John Jacob Astor. He was the fourth child of William Waldorf Astor, 1st Viscount Astor. Lord Astor of Hever was succeeded by his eldest son, the second Baron. He served as Lord Lieutenant of Kent between 1972 and 1982. s of 2013 the title is held by the latter's eldest son, the third Baron, who succeeded in 1984. He is one of the ninety elected hereditary peers who remain in the House of Lords after the passing of the House of Lords Act of 1999, and sits on the Conservative benches. As a descendant of the first Viscount Astor, Lord Astor of Hever is also in remainder to this peerage and its subsidiary title Baron Astor, of Hever Castle in the County of Kent.
ground_truth: Prime Minister of the United Kingdom from 1955 to 1957