Harold Edward Holt was born in Sydney on 5 August 1908.
After studying law at the University of Melbourne, he practised as a solicitor before being elected to Federal Parliament in 1936.
After a thirty-year career in politics, he became Prime Minister following the retirement of Sir Robert Menzies in January 1966.
Holt’s time as Prime Minister was noted in particular for his gradual dismantling of the controversial White Australia policy which had restricted access for migrants of non-European background.
Another major change under the Holt government were two significant changes in the Australian Constitution: power was given to the Federal Parliament to legislate on behalf of the Indigenous people, and the discriminatory clause under which Indigenous people were not counted in the census was removed.
On Sunday 17 December 1967, just one week before the Holt family were due to leave for their Christmas break at Portsea on the Mornington Peninsula, south of Melbourne, Holt went swimming at Cheviot Beach at Point Nepean, not far from Portsea.
After plunging into the notoriously rough surf, Holt disappeared. He was never seen again, and theories as to his fate have abounded since then.
These theories include that he committed suicide, faked his own death in order to run away with his mistress, or that he was a Chinese spy.
Despite an extensive search, neither his body nor any trace of his clothes was ever found. He was officially presumed dead on 19 December 1967.