The Dominion League was formed at a public meeting at His Majesty's Theatre on 30 July 1930. It followed on from the far less successful Secession League which had been established in 1926 by the editor of the Sunday Times James MacCallum Smith. The League was established to agitate for the separation of Western Australia from the Commonwealth and the creation of Western Australia as a Dominion within the British Empire. As the secession song Liberty's Light proclaimed:

Westralia's law, Westralia's will;
Our loyalty, 'England and Empire' still.

Talk of secession had been around since Federation, but the Dominion League very rapidly became a dynamic and influential movement within Western Australian politics. Although proclaiming itself to be non-political, many of its members and supporters were politically conservative. The driving force behind the movement was its young Secretary H.K. 'Keith' Watson, later a Liberal Party MLC, who bombarded newspapers with a constant stream of correspondence and articles advocating the advantages of secession.

Established at a time when the effects of the Depression were just starting to bite in Western Australia, the League claimed at one stage to have as many as 10,000 members recruited through a constant barrage of campaigning by committed activists who would speak on any occasion whether it was on a street corner or at one of the many large public gatherings organised by the League.

Rousing songs like This Bit of the World Belongs to Us and Westralia Free were composed, published, circulated and sung at political meetings in order to strengthen the cause of secession. A direct grassroots campaign was used at a time when the fabric of the Western Australian community was under extreme economic and social pressure.

The Dominion League gave people an opportunity to take action at a time when they felt powerless, providing Western Australians with a handy scapegoat to blame for their problems. To a large extent the Dominion League provided an outlet for discontent. While it was active Western Australia did not develop any organised fascist movement and communist organisations remained very small.