Jack Lang was born on the 21st December 1876 in George Street, Sydney, and was educated at St Francis Marist Brothers' School in Haymarket. In 1901 he moved to Auburn to work as a land agent and auctioneer. He was personally imposing, tall and unsmiling, cultivated an air of middle-class respectability, and espoused an attitude of egalitarianism and radicalism.
In 1903 Lang joined the Granville Labor League, and became active in the local politics of what was then outer suburban Sydney. In 1913 he was elected to the NSW Parliament as Member for Granville. The mass expulsions from the Labor Party in 1917 during the split over conscription allowed Lang to consolidate some power in the NSW ALP, supported by the powerful Australian Workers Union (AWU). His power within the labour movement grew again when he became a director of the Labor Daily newspaper.
In Parliament he earned a reputation for abrasiveness, stubbornness, and ferocity, and within the Party and Labor Caucus his authoritarianism and constant intriguing gained him the enmity of many of his colleagues. Within the ALP he made every attempt to centralise political power, for instance, by insisting that he and not Caucus select candidates for the Legislative Council, and his opponents in the Party and outside labelled him 'dictator'. Certainly, as Premier and as an individual, he behaved as a hater and a loner.
When the Australian economy followed other countries' economic collapse in 1929, Lang put forward a number of radical policies. He proposed to meet State financial obligations to bondholders in the UK only after funding dole payments to unemployed workers, to introduce a new form of currency, and to artificially limit the interest on government borrowings, policies which pit the NSW Labor Government against the Federal Labor Government, not to mention against the other States. The political battle caused the second of Labor's twentieth-century 'splits', and after Lang refused in 1931 to pay interest due on State loans, Labor candidates began to oppose each other as different Parties in elections across the state. Socially, unrest prevailed; though he was himself an opponent of Communism, conservative opinion feared a Langite revolution, and right-wing paramilitary organisations like the New Guard fed on the sense of danger and grievance Lang's government inspired.
In 1932, NSW Governor Sir Philip Game dismissed Lang's government over the issue of non-payment of Federal obligations. In opposition, Lang's popular appeal withered, though his malignant influence on the Labor Party itself continued. Throughout the 1930s in NSW the split became entrenched, "Federal" candidates opposing "Official" candidates, all to Labor's electoral detriment. It took anti-Lang campaigners, including future Prime Minister Ben Chifley and future Premier Robert Heffron, more than a decade to recreate the Labor Party in NSW. The 1940s saw Lang refocus all his bitterness against his Labor opponents now in Government, and after he won the Federal seat of Reid in 1946, he provided harsh and vicious criticism of Chifley from the cross-benches. Through the 1950s and 1960s Lang wrote, lectured, and toured as a public speaker, reinventing himself as a populist. Lang died on the 27th September 1975, and was buried at Rookwood Cemetery in Sydney.