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

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. <SEP> 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.  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.  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.  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. <SEP> Han Myeong-sook (born March 24, 1944; Korean: 한명숙 ] ) was the Prime Minister of South Korea from April 2006 to March 2007.  She is South Korea's first female prime minister (second female prime minister overall if the acting premiership of Chang Sang is included).  She was from the United New Democratic Party (UNDP) as a member of the Korean National Assembly (representative) for Ilsan-gab, and is a graduate of Ewha Womans University in Seoul with a degree in French literature.  She resigned as Prime Minister on March 7, 2007 and declared her presidential candidacy.  But she did not succeed in the nominations.  In 2008 she ran for parliament, but was not elected.  However, in January 2012 she was elected leader of the main oppositional Democratic United Party (DUP) before the April legislative elections and became a member of parliament.  But the liberals did not manage to defeat the ruling Saenuri Party and Han stepped down as party leader in April 2012.  In August 2015, Han was convicted of receiving illegal donations at the amount of 900 million KRW, and sentence to two years in prison.  She is ineligible to run for public office for ten years after her prison term.  She became the first former prime minister of the Republic of Korea to serve a prison time. <SEP> Viscount Brentford, of Newick in the County of Sussex, is a title in the Peerage of the United Kingdom.  It was created in 1929 for the Conservative politician Sir William Joynson-Hicks, 1st Baronet, chiefly remembered for his tenure as Home Secretary from 1924 to 1929.  He had already been created a baronet, of Holmsbury, in the Baronetage of the United Kingdom, on 20 September 1919.  His younger son, the third Viscount, was also a Conservative politician.  On 29 January 1956, two years before he succeeded his elder brother in the viscountcy, he was created a baronet, of Newick.  s of 2017 the titles are held by the third Viscount's son, the fourth Viscount, who succeeded in 1983, a retired solicitor and has served as the president of the Church Society.