He was the first person to hold the office of premier in its own right, and not an additional duty taken up by the Treasurer, Attorney-General or Chief Secretary.

Dunstan was born on 26 July 1882 at Donald East, a rural locality in the Mallee region of the colony of Victoria.

After moving to Bendigo he joined the local branch and was endorsed as the union's candidate for the seat of Eaglehawk at the 1920 state election.

Allan subsequently led the Country Party into a coalition government with the Nationalists under Lawson and Alexander Peacock, with Dunstan not receiving ministerial office.

Henry Bolte, later Victoria's longest-serving premier, was 27 in 1935, and Dunstan's betrayal of Argyle lay behind his lifelong and intense dislike of the Country Party, whom he called "political prostitutes".

On 14 September 1943, Dunstan resigned when his government lost a vote of no confidence in the Victorian Legislative Assembly on the issue of electoral redistribution.

Cain's motion to adjourn the parliament for over a week was defeated by the Country Party and the UAP, and Dunstan moved that Parliament resume the next day, giving notice that he would move a motion of no confidence against Cain's government, confident it would be carried by the CP–UAP alliance.

Dunstan resigned as leader of the Country Party after the 1945 state election, which saw the ALP make significant gains.

At McDonald's insistence, he returned to the ministry following the 1947 state election, which saw a Liberal–Country coalition government headed by Thomas Hollway.