Question: Who was the oldest Prime Minister to pay homage at the funeral of Margaret Thatcher?

full_context: Document 1: David Cameron: David William Donald Cameron ( ; born 9 October 1966) is a British politician who was Prime Minister of the United Kingdom from 2010 to 2016 and Leader of the Conservative Party from 2005 to 2016. He was Member of Parliament (MP) for Witney from 2001 to 2016. Cameron identifies as a One-Nation Conservative, and has been associated with both economically liberal and socially liberal policies.
Document 2: Conservative Party (UK) leadership election, 1997: The 1997 Conservative Party leadership election was triggered in the British Conservative Party when John Major resigned on 2 May 1997, following his party's defeat at the 1997 general election, which ended 18 years of Conservative Government of the United Kingdom. Major had been Conservative leader and Prime Minister since November 1990.
Document 3: Death and funeral of Margaret Thatcher: Baroness Thatcher died of a stroke in London on 8 April 2013 at the age of 87. On 17 April, the former Prime Minister was honoured with a ceremonial funeral. Due to the polarised view of her achievements and legacy, reaction to her death was mixed throughout the United Kingdom, with her memory evoking both intense praise and criticism. The funeral, including a formal procession through Central London, followed by a church service at St Paul's Cathedral, cost around £3.6 million including £3.1 million for security. The funeral was notable for the attendance of Queen Elizabeth II. All four of her successors as Prime Minister paid homage at the funeral. Her body was cremated at Mortlake Crematorium following the funeral.
Document 4: 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 5: 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 6: John Major: Sir John Major, {'1': ", '2': ", '3': ", '4': "} (born 29 March 1943) is a British politician who was Prime Minister of the United Kingdom and Leader of the Conservative Party from 1990 to 1997. He served as Foreign Secretary and then Chancellor of the Exchequer in the Thatcher Government from 1989 to 1990, and was the Member of Parliament (MP) for Huntingdon from 1979 until he retired in 2001. Since Margaret Thatcher's death in 2013, he is the oldest living former Prime Minister.
Document 7: Keith Joseph: Keith Sinjohn Joseph, Baron Joseph, (17 January 1918 – 10 December 1994), known as Sir Keith Joseph, 2nd Baronet, for most of his political life, was a British barrister and politician. A member of the Conservative Party, he served in the Cabinet under four prime ministers: Harold Macmillan, Sir Alec Douglas-Home, Edward Heath and Margaret Thatcher. He was a key influence in the creation of what came to be known as "Thatcherism" and the subsequent decline of one-nation conservatism and the postwar consensus.
Document 8: Diana, Princess of Wales Tribute Concert: The Diana, Princess of Wales Tribute Concert was a British music concert held in memory of Diana, Princess of Wales on 27 June 1998, a few days before the date of what would have been her 37th birthday. The concert was held at Althorp Park, the Northamptonshire seat of the Spencer family, and Diana's childhood home. Artists and groups who performed at the concert were among those enjoyed by the late Princess, and included Sir Cliff Richard, Chris de Burgh, David Hasselhoff, Duran Duran, Jimmy Ruffin and Lesley Garrett. The concert was attended by 15,000 people, with proceeds from ticket sales being donated to the Diana, Princess of Wales Memorial Fund, but the £39.50 price attracted criticism due to its perceived expense. Phil Collins, who did not appear at the concert, was among those to comment on the amount charged to concertgoers. Highlights of the concert were broadcast on BBC One on the evening of 1 July.
Document 9: Tony Blair: Anthony Charles Lynton Blair (born 6 May 1953) is a British politician who served as Prime Minister of the United Kingdom from 2 May 1997 to 27 June 2007 and Leader of the Labour Party from 21 July 1994 to 24 June 2007. He previously served as Leader of the Opposition from 21 July 1994 to 2 May 1997. He is the most recent British Labour Party leader to have won a general election.
Document 10: Later life of Winston Churchill: The later life of Winston Churchill documents the life of the British statesman from the end of World War II and his second term as Prime Minister of the United Kingdom, until his subsequent death and funeral in 1965. After the end of the war Churchill had to step down as Prime Minister of the United Kingdom because the Conservative Party lost the 1945 election. For six years he was to serve as the Leader of the Opposition. During these years Churchill continued to influence world affairs; in 1946 he gave his Iron Curtain speech which spoke of the expansionist policies of the USSR and the creation of the Eastern Bloc; Churchill also argued strongly for British independence from the European Coal and Steel Community (which he saw as a Franco-German project as Britain still had an empire). In the General Election of 1951 Labour was defeated and Churchill became Prime Minister for a second time. Churchill continued to lead Britain but was to suffer increasingly from health problems. Aware that he was slowing down both physically and mentally he resigned from the Cabinet in 1955. However he continued to sit as an MP for Woodford until he retired from politics in 1964. Churchill died on 24 January 1965 and was granted the honour of a state funeral. He was buried in his family plot in St Martin's Church, Bladon near to where he was born at Blenheim Palace.
Document 11: Sapphire Jubilee of Queen Elizabeth II: On 6 February 2017, the Sapphire Jubilee of Queen Elizabeth II, marking sixty-five years of her reign, occurred. The longest-reigning monarch in British history, Queen Elizabeth II was the first British monarch to have a sapphire jubilee. This Jubilee featured blue stamps from the Royal Mail, commemorative coins from the Royal Mint, and a reissue of an official 2014 portrait of Queen Elizabeth II by David Bailey. In this official portrait the Queen wears sapphire jewellery which she received as a wedding present from her father. The Jubilee also involved a gun salute at the Tower of London, a gun salute in Green Park, gun salutes in several other places around the United Kingdom, and the ringing of the bells in Westminster Abbey. Theresa May, the Prime Minister of the United Kingdom, congratulated Queen Elizabeth II in regard to the occasion, saying in part, "I know the nation will join with me today in celebrating and giving thanks for the lifetime of service Her Majesty the Queen has given to our country and to the Commonwealth."
Document 12: 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 13: Reactions to the 2017 Manchester Arena bombing: The reactions to the 2017 Manchester Arena bombing include the responses by political and religious leaders, media and the general public, both within the United Kingdom, where the 2017 Manchester Arena bombing took place, and from other nations and international organizations. Numerous notable establishments around the world also held memorials.
Document 14: James Callaghan: Leonard James Callaghan, Baron Callaghan of Cardiff, {'1': ", '2': ", '3': ", '4': "} (27 March 1912 – 26 March 2005), often known as Jim Callaghan, was a British politician who served as Prime Minister of the United Kingdom from 1976 to 1979 and Leader of the Labour Party from 1976 to 1980. Callaghan is to date, the only British politician in history to have served in all four of the "Great Offices of State", having been Chancellor of the Exchequer from 1964–67, Home Secretary from 1967-70, and Foreign Secretary from 1974, until his appointment as Prime Minister in 1976. As Prime Minister, he had some successes, but is mainly remembered for the "Winter of Discontent" of 1978–79. During a very cold winter, his battle with trade unions led to massive strikes that seriously inconvenienced the public, leading to his defeat in the polls by Conservative leader Margaret Thatcher.
Document 15: 1987 in the United Kingdom: Events from the year 1987 in the United Kingdom. At the beginning of the year, the Archbishop of Canterbury's envoy Terry Waite was kidnapped in Lebanon and remained a hostage until 1991. The major political event of this year was the re-election of Margaret Thatcher in June, making her the longest continuously serving Prime Minister since Lord Liverpool in the early 19th century. The year was also marked by a number of disasters — the sinking of the ferry MS "Herald of Free Enterprise", the Hungerford massacre, the "Great Storm", the Remembrance Day Bombing and the King's Cross fire.
ground_truth: Sir John Major