High Quality Content by WIKIPEDIA articles! Sir Joseph Cook, GCMG (7 December 1860 – 30 July 1947) 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.