13 December 1974 and became the current Republic of Malta, a republic within the Commonwealth. Mintoff remained in office as the republic's first prime minister until 22 December 1984. Mauritius Mauritius became independent on 12 March 1968, with Seewoosagur Ramgoolam becoming the first prime minister. Ramgoolam had previously been Chief Minister of Mauritius. Reference Mauritius abolished the monarchy on 12 March 1992. Jugnauth remained in office as the republic's prime minister until 15 December 1995. New Zealand Sidney Holland was the incumbent prime minister when Elizabeth became queen. Nigeria The Federation of Nigeria became independent on 1 October 1960, with Abubakar Tafawa Balewa becoming the first prime minister. Balewa had previously been Chief Minister of the Colony and Protectorate of Nigeria. Reference Nigeria became the Federal Republic of Nigeria on 1 October 1963. Balewa remained in office as the republic's prime minister until his overthrow and assassination in the 1966 Nigerian coup d'état on 15 January 1966. Pakistan Khawaja Nazimuddin was the incumbent prime minister when Elizabeth became queen. Reference Pakistan abolished the monarchy on 23 March 1956. Ali remained in office as the republic's first prime minister until 12 September 1956. Papua New Guinea Papua New Guinea became independent on 16 September 1975 with Michael Somare as the first prime minister. Somare had previously been Chief Minister of Papua New Guinea. Reference Saint Kitts and Nevis Saint Kitts and Nevis became independent on 19 September 1983 with Kennedy Simmonds as the first prime minister. Simmonds had previously been Premier of Saint Kitts and Nevis. Reference Saint Lucia Saint Lucia became independent on 22 February 1979 with John Compton as the first prime minister. Compton had previously been Premier of Saint Lucia. Reference Saint Vincent and the Grenadines Saint Vincent and the Grenadines became independent on 27 October 1979 with Milton Cato as the first prime minister. Cato had previously been Premier of Saint Vincent. Reference Sierra Leone Sierra Leone became independent on 27 April 1961, with Milton Margai as the first prime minister. Margai had previously been Prime Minister of the Protectorate of Sierra Leone. Reference Siaka Stevens assumed the role of prime minister following his party's narrow victory in the 1967 general election. However, immediately after taking office, Stevens was deposed by the National Reformation Council in a coup d'état and placed under house arrest. Military rule persisted until an April 1968 counter-coup restored Stevens' premiership. Sierra Leone