Sir Joseph Cook, GCMG was an Australian politician and the sixth Prime Minister of Australia. Born as Joseph Cooke and working in the coal mines of Silverdale, Staffordshire during his early life, he emigrated to Lithgow, New South Wales during the late 1880s, and became General-Secretary of the Western Miners Association in 1887.
A founding member of the Australian Labor Party, Cook was elected to the New South Wales Legislative Assembly as Member for Hartley in 1891. Later Cook switched to the Free Trade Party, and was a minister in the cabinet of Premier George Reid from 1894 to 1899. During Australia's first federal election in 1901, Cook was elected unopposed to the federal seat of Parramatta, and served as the deputy to Reid, then Alfred Deakin, following the creation of the Commonwealth Liberal Party from Cook's and Deakin's parties.
As leader of the Liberal Party, Cook became Prime Minister following the 1913 elections; but he only had a one-seat majority in the lower house and no majority at all in the upper house, so he repeatedly sought to obtain a double dissolution. The outbreak of World War I just before the September 1914 election led to a Labor victory. Following a split in the Labor party in 1916, Cook joined William Morris Hughes' Nationalist Party of Australia, and following the Nationalist victory in the 1917 election, served as Minister for the Navy, then Treasurer under Hughes.