Question: What was the politician's position that was in the biography Percy Jackson wrote?

full_context: Document 1: List of Prime Ministers of the United Kingdom: The Prime Minister of the United Kingdom is the head of the Government of the United Kingdom, and chairs Cabinet meetings. There is no specific date when the office of Prime Minister first appeared, as the role was not created but rather evolved over a period of time. The term was used in the House of Commons in 1805 and it was certainly in parliamentary use by the 1880s, and in 1905 the post of Prime Minister was officially given recognition in the order of precedence. Modern historians generally consider Sir Robert Walpole, who led the government of Great Britain from 1721 to 1742, as the first Prime Minister. Walpole is also the longest-serving Prime Minister by this definition. However, Sir Henry Campbell-Bannerman was the first Prime Minister and Margaret Thatcher the longest-serving Prime Minister to have been officially referred to as such.
Document 2: Don Watson: Watson was born in Warragul in the Gippsland region of Victoria, and grew up on a farm in nearby Korumburra. He took his undergraduate degree at La Trobe University and a PhD at Monash University and was for ten years an academic historian. He wrote three books on Australian history before turning his hand to TV and the stage. For several years he combined writing political satire for the actor Max Gillies with political speeches for the then Premier of Victoria, John Cain. In 1992 he became Prime Minister of Australia Paul Keating's speech-writer and adviser and his best-selling account of those years, "Recollections of a Bleeding Heart: A Portrait of Paul Keating PM", won both The Age Book of the Year and non-fiction Prizes, the "Courier-Mail" Book of the Year, the National Biography Award and the Australian Literary Studies Association's Book of the Year. In addition to regular books, articles and essays, in recent years he has also written feature films, including "The Man Who Sued God", starring Billy Connolly and Judy Davis, and "Passion", a film about Percy Grainger starring Richard Roxburgh.
Document 3: Percy Joske: Sir Percy Ernest Joske, CMG (5 October 1895 – 25 April 1981) was an Australian politician. Born in Melbourne, he attended Wesley College and then the University of Melbourne before being called to the bar in 1917. He served in the military 1943-45, and returned to become a law lecturer at the University of Melbourne, a position he held from 1949 to 1952. He was also an author. In 1951, he was elected to the Australian House of Representatives as the Liberal member for the blue-ribbon seat of Balaclava, being elected in the by-election following the resignation of Thomas White. Joske resigned in 1960 to become Judge of the Commonwealth Industrial Court. He was subsequently appointed to the Supreme Court of the Australian Capital Territory (1960–77) and the Supreme Court of the Northern Territory (1961–77). He was knighted in 1967, and died in 1981; a year before his death, he published a biography of Sir Robert Menzies.
Document 4: Roger Goldsworthy (politician): Eric Roger Goldsworthy, AO was an Australian politician and 3rd Deputy Premier of South Australia from 1979 to 1982. Goldsworthy represented the House of Assembly seat of Kavel for the Liberal and Country League and Liberal Party of Australia from 1970 to 1992. Before entering Parliament he was a farmer and teacher. He was also a member of University of Adelaide Council 1970–1973. He became deputy leader of the SA Liberals, and hence Deputy Leader of the Opposition, in 1975 when David Tonkin successfully challenged Bruce Eastick's leadership. As such, he became Deputy Premier when the Liberals won the 1979 state election, also serving as Minister of Mines and Energy, Services and Supply. He remained deputy leader when the Liberals went back into opposition in 1982, returning to the backbench in 1989.
Document 5: Menzies Government (1949–66): The Menzies Government (1949–1966) refers to the period of federal Executive Government of Australia led by Prime Minister Robert Menzies. It was made up of members of a Liberal Party of Australia-Country Party of Australia coalition in the Australian Parliament from 1949–1966. Menzies led the Liberal-Country Coalition to election victories in 1949, 1951, 1954, 1955, 1958, 1961 and 1963. Robert Menzies was Australia's longest serving Prime Minister. He had served a previous term as Prime Minister as leader of the United Australia Party from 1939–1941.
Document 6: Mal Bryce: Malcolm John "Mal" Bryce AO (born 10 April 1943) is a former Australian politician who was a Labor Party member of the Legislative Assembly of Western Australia from 1971 to 1988, representing the seat of Ascot. He was deputy leader of the Labor Party from 1977 to 1980 and from 1981 to 1988, and served as deputy premier under Brian Burke.
Document 7: Harold Holt: Harold Edward Holt, {'1': ", '2': ", '3': ", '4': "} ( ; 5 August 190817 December 1967), was an Australian politician and the 17th Prime Minister of Australia from 1966 to 1967. He was born in Stanmore, New South Wales and won a scholarship to study law at the University of Melbourne. Holt went into business as a solicitor, during which time he joined the United Australia Party (UAP). In 1935, aged just 27, he was elected to parliament for Fawkner. He held this seat until 1949, when he transferred to Higgins. Holt spent 32 years in Parliament, including many years as a senior Cabinet Minister, but was Prime Minister for only 22 months before he disappeared in December 1967 while swimming at Cheviot Beach near Portsea, Victoria and was presumed drowned.
Document 8: Lance Shilton: He was born in late 1921 in Elsternwick, Victoria, a suburb of Melbourne, and educated at the University of Melbourne and ordained in 1950. His first post was as a curate at Hawthorn. Then he was the incumbent at Carlton from 1951 to 1954. After this he was at the University of London for two years completing a B.D. From 1957 to 1973 he was the Rector of Holy Trinity, Adelaide.
Document 9: Tony Abbott: Anthony John Abbott (born 4 November 1957) is an Australian politician who was the 28th Prime Minister of Australia, from 18 September 2013 to 15 September 2015. Abbott was leader of the Liberal Party of Australia from 2009 to 2015, and has been a member of parliament for Warringah since 1994.
Document 10: Walter Leslie Duncan: Walter Leslie Duncan (14 February 1883 – 28 May 1947) was an Australian politician. Born in Armidale, New South Wales, he was educated at state schools before becoming a clerk, and was President of the Labor Council of New South Wales in 1911. A member of the Labor Party, he joined the Nationalists in the wake of the 1916 split over conscription. Duncan enlisted in the military in 1917, leaving in 1919 to successfully contest the Senate for the Nationalists. A strong supporter of Billy Hughes, he was excluded from the party along with Hughes in 1929 and joined the Australian Party, before being reaccepted into the United Australia Party in 1931. He resigned from the Senate in 1931. He was also a Director of the Adelaide Steamship Company for many years. Duncan died in 1947.
Document 11: Douglas Menzies: Sir Douglas Ian Menzies KBE (7 September 190729 November 1974) was an Australian judge, serving as a Justice of the High Court of Australia. He was also Chancellor of Monash University from 1968 until his death in 1974.
Document 12: Malcolm Turnbull: Malcolm Bligh Turnbull (born 24 October 1954) is the 29th and current Prime Minister of Australia. He first served as parliamentary leader of the Liberal Party and as opposition leader from 2008 to 2009, and became parliamentary leader and Prime Minister after defeating Tony Abbott at the 2015 Liberal leadership spill. The Turnbull Government was re-elected at the 2016 federal election, but with only a one-seat majority.
Document 13: Roland Perry: Roland John Perry OAM (born 11 October 1946) is a Melbourne-based author best known for his books on history, especially Australia in the two world wars. His "Monash: The Outsider Who Won The War", won the Fellowship of Australian Writers' 'Melbourne University Publishing Award' in 2004. The judges described it as 'a model of the biographer's art.' In the Queen's Birthday Honours of 2011, Perry was awarded the Medal of the Order of Australia 'for services to literature as an author.' In October 2011, Monash University awarded Perry a Fellowship for 'high achievement as a writer, author, film producer and journalist.' His sports books include biographies of Sir Donald Bradman, Steve Waugh, Keith Miller and Shane Warne. Perry has written on espionage, specialising in the British Cambridge Five ring of Russian agents. He has also published three works of fiction and produced more than 20 documentary films. Perry has been a member of the National Archives of Australia Advisory Council since 2006. In late 2012 Perry accepted an adjunct appointment at Monash University as a Professor, with the title ‘Writer-in-Residence’ in the University’s Arts Faculty.
Document 14: 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 15: Robert Menzies: Sir Robert Gordon Menzies, {'1': ", '2': ", '3': ", '4': "} (20 December 189415 May 1978), was the Prime Minister of Australia from 1939 to 1941 and again from 1949 to 1966. He is Australia's longest-serving prime minister, serving over 18 years in total.
ground_truth: Prime Minister