Albert "Jupp" Gardiner was an Australian politician who served as a Senator for New South Wales from 1910 to 1926 and again briefly in 1928. A member of the Labor Party, he served in cabinet as Vice-President of the Executive Council under Andrew Fisher and Billy Hughes, and from 1916 to 1926 was his party's Senate leader; he was its only senator from 1920 to 1922. Before entering federal politics he had served in the Parliament of New South Wales from 1891 to 1895 and from 1904 to 1907.

James Henry Scullin was an Australian politician and trade unionist who served as the ninth prime minister of Australia from 1929 to 1932. He held office as the leader of the Australian Labor Party (ALP), having briefly served as treasurer of Australia during his time in office from 1930 to 1931. His time in office was primarily categorised by the Wall Street Crash of 1929 which transpired just two days after his swearing in, thus heralding the beginning of the Great Depression in Australia. Scullin remained a leading figure in the Labor movement throughout his lifetime, and was an éminence grise in various capacities for the party until his retirement from federal parliament in 1949. He was the first Catholic, as well as the first Irish-Australian, to serve as prime minister.