Early life

Slater is believed to have been born in 1890. He was born to parents of Irish

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

 background. His father left his family when he was four years old. He and two siblings were brought up by his mother in Prahran

Prahran, Victoria

Prahran , also known colloquially as "Pran", is a suburb in Melbourne, Victoria, Australia, 5 km south-east from Melbourne's central business district. Its Local Government Area is the City of Stonnington. At the 2006 Census, Prahran had a population of 10,651. It is a part of Melbourne with...

. After briefly attending Armadale State School Slater left school early to sell newspapers. Being caught and fined for nude swimming in the Yarra River

Yarra River

The Yarra River, originally Birrarung, is a river in east-central Victoria, Australia. The lower stretches of the river is where the city of Melbourne was established in 1835 and today Greater Melbourne dominates and influences the landscape of its lower reaches...

 led him to decide to better himself. Using a free library and with support from the Try Boys' Society he was able to educate himself to the point he was able to be employed as an office boy.

In 1910 he was employed as a clerk for Percy Park, a solicitor based in Mildura

Mildura, Victoria

Mildura is a regional city in northwestern Victoria, Australia and seat of the Rural City of Mildura local government area. It is located in the Sunraysia region, and is on the banks of the Murray River. The current population is estimated at just over 30,000.Mildura is a major agricultural centre...

. While living in Mildura, Slater saved enough money to buy two small fruit properties.

War

As a socialist, Slater initially refused to enlist with the Australian Imperial Force

Australian Imperial Force

The Australian Imperial Force was the name given to all-volunteer Australian Army forces dispatched to fight overseas during World War I and World War II.* First Australian Imperial Force * Second Australian Imperial Force...

 at the beginning of World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

. However, spurred on by the aftermath of the Gallipoli campaign, he decided to enlist with the AIF. His first attempt to enlist was unsuccessful as he was deemed unsuitable for service due to varicose veins

Varicose veins

Varicose veins are veins that have become enlarged and tortuous. The term commonly refers to the veins on the leg, although varicose veins can occur elsewhere. Veins have leaflet valves to prevent blood from flowing backwards . Leg muscles pump the veins to return blood to the heart, against the...

. After an operation to fix the ailment he enlisted in December 1915 with the 10th Field Ambulance.

Slater left Melbourne

Melbourne

Melbourne is the capital and most populous city in the state of Victoria, and the second most populous city in Australia. The Melbourne City Centre is the hub of the greater metropolitan area and the Census statistical division—of which "Melbourne" is the common name. As of June 2009, the greater...

 with his unit in June 1916, arriving in Plymouth

Plymouth

Plymouth is a city and unitary authority area on the coast of Devon, England, about south-west of London. It is built between the mouths of the rivers Plym to the east and Tamar to the west, where they join Plymouth Sound...

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 in August of the same year. In November he was disciplined for poor conduct. In July 1917 he was wounded in action, sustaining a gunshot wound to the leg.

Public life

While recovering in an English hospital he agreed to stand for election to the Victorian Legislative Assembly

Victorian Legislative Assembly

The Victorian Legislative Assembly is the lower house of the Parliament of Victoria in Australia. Together with the Victorian Legislative Council, the upper house, it sits in Parliament House in the state capital, Melbourne.-History:...

. In November 1917 he was elected to the seat of Dundas. The Argus

The Argus (Australia)

The Argus was a morning daily newspaper in Melbourne established in 1846 and closed in 1957. Widely known as a conservative newspaper for most of its history, it adopted a left leaning approach from 1949...

 newspaper later reported that fellow patients at the hospital mistook his appointment as a Member of Parliament as being a promotion to the Military Police.

He left for Australia in early 1918. Returning to Australia he was arrested by military police in Fremantle

Fremantle

Freemantle is a suburb of Southampton in England.Fremantle or Freemantle may also refer to:- Places :* Fremantle, the port city to the capital Perth, Western Australia...

 for speaking in defence of John Curtin

John Curtin

John Joseph Curtin , Australian politician, served as the 14th Prime Minister of Australia. Labor under Curtin formed a minority government in 1941 after the crossbench consisting of two independent MPs crossed the floor in the House of Representatives, bringing down the Coalition minority...

, then the editor of a trade union newspaper. He was discharged from active service due to a recurrence of his varicose veins.
On his return to Victoria he was engaged by Maurice Blackburn as an articled clerk

Articled clerk

An articled clerk, also known as an articling student, is an apprentice in a professional firm in Commonwealth countries. Generally the term arises in the accountancy profession and in the legal profession. The articled clerk signs a contract, known as "articles of clerkship", committing to a...

. When he was admitted as a barrister and solicitor in 1922 he became a partner in Blackburn's practice which was renamed Blackburn and Slater.

In July 1924 he was appointed Attorney General

Attorney General

In most common law jurisdictions, the attorney general, or attorney-general, is the main legal advisor to the government, and in some jurisdictions he or she may also have executive responsibility for law enforcement or responsibility for public prosecutions.The term is used to refer to any person...

 and Solicitor General

Solicitor-General of Victoria (Australia)

The Solicitor-General of Victoria, Australia is the state's Second Law Officer, behind the Attorney-General. The holders of this office are appointed by Cabinet on the basis of their legal expertise. Solicitors-General are members of the Executive...

 in the Prendergast

George Prendergast

George Michael Prendergast , Australian politician, was the 28th Premier of Victoria. He was born to Irish emigrant parents in Adelaide, but he grew up in Stawell in the Wimmera district of Victoria...

 government which only last five months. He was given the same cabinet posts under the premierships of Edmond Hogan

Edmond Hogan

Edmond John "Ned" Hogan , Australian politician, 30th Premier of Victoria, was born in Wallace, Victoria, where his Irish-born parents were small farmers...

 in 1927-1928 and 1929-1932.

In 1935 he entered into partnership with Hugh Gordon, his brother-in-law, forming Slater & Gordon

Slater & Gordon

Slater & Gordon, founded in Melbourne in 1935 by Labor politician William Slater and Hugh Lyon Gordon, is an Australian law firm employing over 800 people across Australia....

.

Slater was appointed as Speaker of the Victorian Legislative Assembly

Speaker of the Victorian Legislative Assembly

The Speaker of the Victorian Legislative Assembly is the presiding officer of the Victorian Legislative Assembly, the lower house of the Parliament of Victoria....

 in 1940.

In 1942 he was appointed by Prime Minister

Prime Minister of Australia

The Prime Minister of the Commonwealth of Australia is the highest minister of the Crown, leader of the Cabinet and Head of Her Majesty's Australian Government, holding office on commission from the Governor-General of Australia. The office of Prime Minister is, in practice, the most powerful...

 John Curtin

John Curtin

John Joseph Curtin , Australian politician, served as the 14th Prime Minister of Australia. Labor under Curtin formed a minority government in 1941 after the crossbench consisting of two independent MPs crossed the floor in the House of Representatives, bringing down the Coalition minority...

 as minister

Envoy (title)

In diplomacy, an Envoy Extraordinary and Minister Plenipotentiary is, under the terms of the Congress of Vienna of 1815, a diplomat of the second class, ranking between an Ambassador and a Minister Resident....

 to the Soviet Union

Soviet Union

The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

, the first Australian diplomatic representative to the country. En route to his new appointment he visited the United States, eventually arriving in the Soviet Union in late 1942. He took residence in Kuybyshev

Samara, Russia

Samara , is the sixth largest city in Russia. It is situated in the southeastern part of European Russia at the confluence of the Volga and Samara Rivers. Samara is the administrative center of Samara Oblast. Population: . The metropolitan area of Samara-Tolyatti-Syzran within Samara Oblast...

 in January 1943. After falling ill in April 1943 he returned to Australia in June. Although the official reason given for his early return was illness, speculation in the Australian press centred on a disillusionment with the Soviet version of Socialism.

Under John Cain

John Cain (senior)

John Cain was an Australian politician, who became the 34th premier of Victoria, and was the first Australian Labor Party leader to win a majority in the Victorian Legislative Assembly. He was the only premier of Victoria whose son also served as premier.-Early life:Cain was born, one of 18...

 he was Attorney General and Solicitor General between 1945 and 1947 when he lost his seat. In 1949 he returned to Parliament in the Victorian Legislative Council

Victorian Legislative Council

The Victorian Legislative Council, is the upper of the two houses of the Parliament of Victoria, Australia; the lower house being the Legislative Assembly. Both houses sit in Parliament House in Spring Street, Melbourne. The Legislative Council serves as a house of review, in a similar fashion to...

 seat of Doutta Galla

Doutta Galla Province

Doutta Galla Province was an electorate of the Victorian Legislative Council until 2006. It was abolished from the 2006 state election in the wake of the Bracks Labor government's reform of the Legislative Council.-Members for Doutta Galla Province:...

. He once again served as Attorney General and Solicitor General between 1952 and 1955.

Death

Slater died in 1960 of a heart attack in South Melbourne

South Melbourne, Victoria

South Melbourne is an inner city suburb in Melbourne, Victoria, Australia, 2 km south from Melbourne's central business district. Its Local Government Area are the Cities of Port Phillip and Melbourne...

. He was survived by his wife and three children.