Question: What was the middle name of the man who headed the Rhodesian Front?

full_context: Document 1: Rhodesian Action Party: The Rhodesian Action Party was a political party in Rhodesia formed in 1977 by a group of Rhodesian Front MPs who were dissatisfied by the leadership of Ian Smith and his attempts to negotiate an 'internal settlement' with African nationalists. Twelve members of the Rhodesia House of Assembly joined the party when it was launched on July 4, 1977.
Document 2: Rhodesia (region): Rhodesia is a historical region in southern Africa whose formal boundaries evolved between the 1890s and 1980. Demarcated and named by the British South Africa Company (BSAC), which governed it until the 1920s, it thereafter saw administration by various authorities. It was bisected by a natural border, the Zambezi. The territory to the north of the Zambezi was officially designated Northern Rhodesia by the Company, and has been Zambia since 1964; that to the south, which the Company dubbed Southern Rhodesia, became Zimbabwe in 1980. Northern and Southern Rhodesia were sometimes informally called "the Rhodesias".
Document 3: P. K. van der Byl: Pieter Kenyon Fleming-Voltelyn van der Byl, GLM ID (11 November 1923 – 15 November 1999) was a Rhodesian politician who served as his country's Foreign Minister from 1974 to 1979 as a member of the Rhodesian Front (RF). A close associate of Prime Minister Ian Smith, Van der Byl opposed attempts to compromise with the British government and domestic black nationalist opposition on the issue of majority rule throughout most his time in government. However, in the late 1970s he supported the moves which led to majority rule and internationally recognised independence for Zimbabwe.
Document 4: Rhodesian Front: The Rhodesian Front (Afrikaans: "Rhodesiese Front" , RF) was a right-wing political party in Rhodesia (or Southern Rhodesia) when the country was under white minority rule. Led first by Winston Field, and, from 1964, by Ian Smith, the Rhodesian Front was the successor to the Dominion Party, which was the main opposition party in Southern Rhodesia during the Federation period. The RF was formed in March 1962 by whites opposed to any immediate change to black majority rule. It won power in the general election that December. In successive elections (in which 50 of the 66 parliamentary seats were reserved for A-Roll voters, who had to meet a higher standard of qualifications, increasing the proportion of white Africans who came under this roll) between 1964 and 1979, the RF was returned to office, with a large majority, with Smith as Prime Minister.
Document 5: Rhodesian constitutional referendum, 1979: A constitutional referendum was held in Rhodesia on 30 January 1979. It followed the Internal Settlement drawn up between Prime Minister Ian Smith and Abel Muzorewa, leader of the non-violent UANC. The new constitution would bring in black majority rule in the country, which would be renamed Zimbabwe Rhodesia. The settlement was supported by the ruling Rhodesian Front, but opposed by the Rhodesian Action Party, which had broken away from the Front.
Document 6: Constitutional history of Zimbabwe: The constitutional history of Zimbabwe starts with the arrival of white people to what was dubbed Southern Rhodesia in the 1890s. The country was initially run by an administrator appointed by the British South Africa Company. The prime ministerial role was first created in October 1923, when the country achieved responsible government, with Sir Charles Coghlan as its first Premier. The third Premier, George Mitchell, renamed the post Prime Minister in 1933.
Document 7: Ian Smith: Ian Douglas Smith, GCLM, ID (8 April 1919 – 20 November 2007) was a politician, farmer, and fighter pilot who served as Prime Minister of Rhodesia (or Southern Rhodesia) from 1964-1979. The country's first premier not born abroad, he led the predominantly white government that unilaterally declared independence from the United Kingdom in 1965, following prolonged dispute over the terms. He remained Prime Minister for almost all of the fourteen years of international isolation that followed, and oversaw Rhodesia's security forces during most of the Bush War, which pitted the unrecognised administration against communist-backed black nationalist guerrilla groups. Smith, who has been described as personifying white Rhodesia, remains a highly controversial figure—supporters venerate him as a man of integrity and vision "who understood the uncomfortable truths of Africa", while critics describe an unrepentant racist whose policies and actions caused the deaths of thousands and contributed to Zimbabwe's later crises.
Document 8: B. J. Vorster: Balthazar Johannes Vorster (] ; 13 December 1915 – 10 September 1983), better known as John Vorster, served as the Prime Minister of South Africa from 1966 to 1978 and as the fourth State President of South Africa from 1978 to 1979. Vorster was known for his staunch adherence to apartheid, overseeing (as Minister of Justice) the Rivonia Trial in which Nelson Mandela was sentenced to life imprisonment for , and (as Prime Minister) the Terrorism Act, the complete abolition of non-white political representation, the Soweto Riots and the Steve Biko crisis. He conducted a more pragmatic foreign policy than his predecessors in an effort to improve relations between the white minority government and South Africa's neighbours, particularly after the break-up of the Portuguese colonial empire. Shortly after the Internal Settlement in Rhodesia, in which he was instrumental, he was implicated in the Muldergate Scandal and resigned the premiership in favour of the ceremonial presidency, which he was forced to give up as well eight months later.
Document 9: Winston Field: Winston Joseph Field MBE (June 6, 1904– March 17, 1969) was a Rhodesian politician. Field was a former Dominion Party MP who founded the Rhodesian Front political party with Ian Douglas Smith.
Document 10: Rhodesia cricket team: The Rhodesia cricket team played first-class cricket and represented originally the British colony of Southern Rhodesia and later the unilaterally independent state of Rhodesia which became Zimbabwe. In 1980 the Rhodesia cricket team was renamed as the Zimbabwe-Rhodesia Cricket team, and in 1981 it adopted its current name of the Zimbabwe national cricket team.
Document 11: Cecil Rhodes: Cecil John Rhodes PC (5 July 1853 – 26 March 1902) was a British businessman, mining magnate and politician in South Africa, who served as Prime Minister of the Cape Colony from 1890 to 1896. An ardent believer in British imperialism, Rhodes and his British South Africa Company founded the southern African territory of Rhodesia (now Zimbabwe and Zambia), which the company named after him in 1895. South Africa's Rhodes University is also named after him. Rhodes set up the provisions of the Rhodes Scholarship, which is funded by his estate, and put much effort towards his vision of a Cape to Cairo Railway through British territory.
Document 12: History of Rhodesia (1965–79): The history of Rhodesia from 1965 to 1979 covers Rhodesia's time as a state unrecognised by the international community following the predominantly white minority government's Unilateral Declaration of Independence on 11 November 1965. Headed by Prime Minister Ian Smith, the Rhodesian Front remained in government until 1 June 1979, when the country was reconstituted as Zimbabwe Rhodesia.
Document 13: Rhodesian general election, 1977: The Rhodesia general election of 1977, the last general election dominated by the white minority, took place on 31 August 1977. Rhodesian Prime Minister Ian Smith, who was conducting negotiations with moderate African nationalists, was forced into an early election by the defection of twelve MPs from his Rhodesian Front party, which denied him the two-thirds majority of the House of Assembly needed to change the constitution. In the event, the Front overwhelmed the breakaway Rhodesian Action Party and all other forces, once again winning every single seat in the 50 seats elected by those of European descent.
Document 14: Propaganda in the Rhodesian Bush War: During the Rhodesian Bush War, informational and political warfare was mounted by each of the involved factions: on one side, the Rhodesian government (led by Prime Minister Ian Smith of the Rhodesian Front); on another, the British government and the Commonwealth of Nations; on a third, the Zimbabwe African National Union (ZANU) and its associated guerrilla army, the Zimbabwe African National Liberation Army (ZANLA); and, on a fourth, the Zimbabwe African People's Union (ZAPU) and its armed wing, the Zimbabwe People's Revolutionary Army (ZIPRA).
Document 15: Edgar Whitehead: Sir Edgar Cuthbert Fremantle Whitehead, {'1': ", '2': ", '3': ", '4': "} , OBE, (8 February 1905 – 22 September 1971) was a Rhodesian politician. He was a longstanding member of the Southern Rhodesian Legislative Assembly, although his career was interrupted by other posts and by illness. In particular he had poor eyesight, and wore very thick glasses, and later suffered deafness whilst in office. As an ally of Sir Roy Welensky, he was Prime Minister of Southern Rhodesia from 1958 to 1962. His government was defeated in the 1962 general election by the Rhodesian Front.
ground_truth: Douglas