The Sovereign Union of First Nations and Peoples
The Sovereign Union of First Nations and Peoples, formed in June 1999, provides the umbrella organisation for Aboriginal nations that have declared their independence, and assists other nations in the process of becoming independent.
The independence movement is based on the notion that Aboriginal nations, despite their dispossession and now legal recognition of their traditional ownership of country, never ceded sovereignty.
To become an independent state, a nation must have a land base, population, the ability to develop an economy and be sustainable, be able to govern, and be able to trade, treaty and enter into international agreements.
Individual nations draw their boundaries and declare their independence through the internationally recognised process by way of Unilateral Declarations of Independence (UDIs).
Why declare Aboriginal nations independence and sovereignty?
According to the People’s Council of the Murrawarri Republic there were 3 legally recognised doctrines that governed the taking over or acquiring of new land under 18th century British and international law: 
- Declaration of war. The British never declared war on any Aboriginal nation.
- Negotiation of a treaty. Convenor of the Sovereign Union and Head of State of the Euahlayi Peoples Republic, Michael Anderson, explains that Aboriginal people have not ceded sovereignty over their lands, which “can only be taken or given away by defeat in war, in which case a peace treaty/pact will have to be signed with each nation”. 
- Principle of terra nullius. This principle assumes that the land had no owners. While Great Britain claimed the land was uninhabited, Aboriginal people were actually living there at the time. And the High Court of Australia abolished the legal fiction of terra nullius in its 1992 Mabo versus Queensland (No 2) ruling.
“[An]other way [of rescinding sovereignty] is by the First Nations ceding all that they have and own under their Law and custom to the new invader or occupier state on conditions agreed upon by the parties concerned,” explains Anderson.
“If neither of these… methods is used then our First Nations remain independent of the colonial occupier state and its laws, which is our position today and has resulted in increasing numbers of Unilateral Declarations of Independence (UDIs) by First Nations.” 
List of independent Aboriginal nations
Nations which have already declared independence include:
The Murrawarri people were the first nation to declare their independence on 30th March 2013. Murrawarri people from the Culgoa River region of northern New South Wales declared their sovereignty of their lands under the name of the Murrawarri Republic, made up of 8 clan groups. The Republic covers an area of about 82,000 square kilometres, bordered by Bourke and Brewarrina in the south and Cunnamulla in the north.
The People’s Council of the Murrawarri Republic (the government of the republic) sent their declaration to the Queen of England requesting documents proving Crown title within 21 days. But no response was received and this was interpreted as proof that indeed the republic was an independent state.
The Murrawarri Republic drafted its own constitution in April 2014.
We didn’t declare our independence from Australia. We declared that we were always independent from Australia.—Fred Hooper, chair of the People’s Council of the Murrawarri Republic 
Euahlayi Peoples Republic
On 3 August 2013 in Dirranbandi, Queensland, key Euahlayi family members and Elders asserted their pre-existing and continuing statehood for the People of the Euahlayi. Ghillar, elected Head of State, had asked Her Majesty Queen Elizabeth II if she could provide them with documents where war was declared against his people or where they voluntarily ceded their sovereignty to Great Britain. Neither was confirmed by the Queen .
Republic of Mbarbaram
This nation west of the Atherton Tablelands, far north Queensland, declared independence in November 2013.
Wiradjuri Central West Republic
On 10th January 2014 Aboriginal people of central west NSW around Wellington declared their independence and statehood and the Wiradjuri Central West Republic. On 22 January 2014 the Wellington Council raised the Wiradjiri Central West Republic flag .
Led by Murrumu Walubara Yidindji (formerly known as Jeremy Geia), members of the Yidindji tribe renounced legal ties with Australia in 2014 and formed the Sovereign Yidindji Government or Yidindji Tribal Nation.
The land they claim stretches south of Port Douglas, through Cairns, inland across the Atherton Tablelands and 80km out to sea. The Yidindji nation has its own driver licensing system.
In what is believed to be the first official recognition of the Aboriginal nation, Indigenous affairs minister, Nigel Scullion, acknowledged the presence of the Yidindji cabinet while speaking to delegates at a national development summit in February 2016.
Murrumu surrendered the documents that accompany citizenship for most of us – a bank account, drivers’ licence, Medicare card, superannuation and a passport. He also changed the number plates on his car to a Yidindji licence plate.
The most important thing to remember is we do have a government now and it has been created with correct procedure in terms of international law… people will know that Yidindji has its own language, it has its own laws, its own authority.—Murrumu Walubara Yidindji 
Yuggera Ugarapul Tribal Peoples
Representing descendants of the Yuggera and Ugarapul Peoples, Undambi, Gorenpul, Wakka Wakka, Turrbul, Yugembeh, Yiman,Yelangi, and Yandai Nations, the Yuggera Ugarapul Tribal Peoples declared their independence in September 2016. Their homeland is the area of Brisbane (Meanjin) and Ipswich. 
Mirrabooka Sovereign United Nations
In November 2017 the Mirrabooka Sovereign United Nations (previously Meanjin Senior Sovereigns) formed, which include the Bidjigal Sovereign Elders of La Perouse, as well as Bidjigal, Darug, Gweagal and Woolangang Peoples. 
Why a republic? – The process of declaring independence
Fred Hooper, chair of the People’s Council of the Murrawarri Republic, explains the process of declaring independence and why they chose to become a republic. 
“[The process of declaring independence] came out of the 40th anniversary of the Aboriginal Tent Embassy, where sovereignty was the main focus of the anniversary. We then consulted other members of the Murrawarri people. We researched forms of independence and forms of republics as well…
“[We] found that a republic was the best for us, because we were never a kingdom. We didn’t have Kings and Queens. And we didn’t claim our seat to the throne through God. We decided to go with a republic.
“We researched declarations of independence. How other countries declared their independence. And we decided to go with something similar to Israel’s declaration of independence through the United Nations in the creation of the state of Israel.
“We wrote the declaration. And then it was a matter of getting people to sign it. We hit the road and went to sporting events and got Murrawarri people to actually sign the declaration.”
“[Our] guiding principles are based on sharing our country. The other thing we don’t want to do is kick people off our country. It’s about benefits for all our citizens, both ancestral and non-ancestral citizens.”
“From there we wrote to Queen Elizabeth II notifying her – because she is the head of state of the country – of our intentions and our declaration…”
“We found that in [the] Mabo [judgement] the High Court said… that the Crown did not gain absolute beneficial ownership to the land. The Crown did not gain allodial title to the land. They did not gain the original title off the Murrawarri to our traditional land.
“So therefore, we felt that our ownership of that land has continued, and that’s supported by Mabo in that statement by the judges.”
Asked why his nation didn’t decide to make a native title claim, Fred responds:
“We found that the Act didn’t work. We found that the Act was established for white Australia and all the benefits went to white Australia. All the benefits, except for one right, the right to negotiate… They can force you into arbitration or they can rule in terms of development. So it’s unjust and unfair legislation.”