Australia officially became the Commonwealth of Australia on the 1st of January 1901, when the British Parliament passed legislation allowing the six Australian colonies to govern in their own right as an independent country.
But it wasn't until the 26th of January 1949 -- almost five decades later and after two World Wars and a Great Depression -- that people living in Australia could officially be known as Australian citizens.
Seven men from Czechoslovakia, Spain, Denmark, Greece, France, Yugoslavia, and Norway were the first people to gain citizenship.
In a ceremony on February the 3rd 1949 in front of then-Prime Minister Ben Chifley, the men renounced their old citizenship and swore an oath as new Australians.
Thiel Marstrand from Norway was one of those men, as documented in this television news report from 1949.
"MARSTRAND: I, Thiel Marstrand...
JUDGE: Swear by almighty God....
MARSTRAND: Swear by almighty God....
JUDGE: That I will be faithful...
MARSTRAND: That I will be faithful...
JUDGE: And bare true allegiance...
MARSTRAND: And bare true allegiance...
JUDGE: To his majesty King George the 6th...
MARSTRAND: To his majesty King George the 6th...
JUDGE: And I will faithfully observe...
MARSTRAND: And I will faithfully observe...
JUDGE: The laws of Australia...
MARSTRAND: The laws of Australia...
JUDGE: And fulfill my duty...
MARSTRAND: And fulfill my duty...
JUDGE: As an Australian citizen.
MARSTRAND: As an Australian citizen."
The federal parliament passed the Australian Citizenship Act on the 21st of December 1948.
The act detailed that "Australian citizenship is a common bond, involving reciprocal rights and obligations, uniting all Australians, while respecting their diversity".
Prior to 1949, people living in Australia were known legally as "subjects" under the British Empire, rather than citizens of Australians.
University of Melbourne Emeritus Professor Brian Galligan says the changes in 1949 were simply a legal technicality.
"In the formal acts like the Naturalisation Act and so on, you became a citizen of the Queen, you didn't become a citizen of Australia although essentially that's what it meant. And Australia, of course, being very much a country of the British Empire. So you could say Australians were citizens really from 1901 and the Citizenship Act in '49 simply used that term in a formal legal way."
Professor Galligan says the push for formal citizenship was in part disillusionment with the British Empire following World War 2 and the need for a greater sense of national unity.
"Australians became more conscious of themselves not as Victorians, or Tasmanians, or New South Welshmen, but of Australians. And so this was, you might say somewhat belatedly, but this was a formal recognition of that fact that now they were Australian citizens and this would be recognised in the (Citizenship) Act."
After a period of low migration during the World Wars and Great Depression, the late 1940s saw an influx of new migrants in the country.
Professor Galligan says those migrants who became Australian citizens had to renounce their previous citizenship as a way to ensure their loyalty to their new country.
"The idea was that if you were a citizen of country A, a citizen of Australia, you should have total allegience to that country. And if you were a citizen as well of another country then you would have a divided allegiance. So when it came -- and I suppose this was fresh in people's minds -- but when it came to war and serving your country, if you were also a citizen of another country that was on the other side, then there would be problems and you would have dual allegiance to those countries. You know, you would have sections of the population that couldn't be trusted and so on."
Thiel Marstrand a migrant from Norway, was one of those first men to become an Australian citizen in 1949.
He migrated in 1948 after surviving the Changi prisoner of war camp in Singapore.
After briefly returning to Norway, he and his family decided to move to Australia after Mr Marstrand received a job offer to manage a plywood mill in Tasmania.
Mr Marstrand passed away at the age of 86 in Tasmania.
His daughter Val Busby -who still lives in Tasmania - says Australia offered him a fresh start, escaping both the memories of Changi and the harsh climate of Norway.
"He found it very cold there because he was very emaciated after the war and he was offered a job to come to Tasmania to manage the plywood mill, the job he had in Malayia as a plywood mill manager. He accepted that and we came to live in Somerset [[Tasmania]]which is not far away from Wynyard about five minutes drive from Wynyard."
Ms Busby says her father rarely talked about his experiences in Changi, instead choosing to detail that time in his memoirs.
Ms Busby says what her father did talk about was how much he loved Australia.
"He was very proud to become an Australian he really wanted to. And he has always been very much an Australian. He loved his country of birth, but Australia was his great love and he loved being here and always very grateful. It's a wonderful country isn't it."
