The firstcolonies of theBritish Empire on the continent ofAustralia were thepenal colony ofNew South Wales, founded in 1788, and theSwan River Colony (later renamedWestern Australia), founded in 1829. Over the next few decades, the colonies ofNew Zealand,Queensland,South Australia,Van Diemen's Land (later renamedTasmania), andVictoria were created from New South Wales, as well as an abortedColony of North Australia. On 1 January 1901, these colonies, excepting New Zealand, becamestates in theCommonwealth of Australia. Since federation, the internal borders have remained mostly stable, except for the creation of some territories with limited self-government: theNorthern Territory fromSouth Australia, to govern the vast, sparsely populated centre of the country; the split of the Northern Territory intoCentral Australia andNorth Australia, and then the quick merger of those back into the Northern Territory; and theAustralian Capital Territory, afederal district ceded from New South Wales.

Outside of the continent, Queensland attempted an expansion intoNew Guinea, but British authorities rejected this; the claim would later be made a British protectorate and ceded to Australia. TheLeague of Nations mandated northeast New Guinea to Australia afterWorld War I, as well asNauru, which was placed under joint Australian-British-New Zealand jurisdiction. These mandates (and, later,United Nationstrust territories) became the independent nations of Nauru andPapua New Guinea in the mid-20th century. Australia has also obtainedseveral small island territories, mainly from earlier British colonies, and has alarge claim onAntarctica.

Key to map colours

  Australian states

  Australian territories and founding colonies

  Area changed by event

Date	Event	Map
25 April 1787	TheColony of New South Wales was created as apenal colony by theKingdom of Great Britain inAustralia east of135° east.[1] Word of the establishment was proclaimed in Australia by GovernorArthur Phillip on 7 February 1788.[2] The commission included "all the islands adjacent in the Pacific Ocean" within the latitudes of 10°37' south and 43°39' south, which included most ofNew Zealand.[1]
11 July 1810	Macquarie Island was discovered byFrederick Hasselborough, who claimed it for theUnited Kingdom and declared it part ofNew South Wales.[3][4]
16 July 1825	New South Wales was extended west to129° east, so that it would include a trading post set up onMelville Island; and the borders of the "islands adjacent in the Pacific Ocean" were moved north to 39°12' south, now including only a small part ofNew Zealand.[5]
3 December 1825	The southern islands ofNew South Wales were made theColony of Van Diemen's Land.[6][7]
2 May 1829	A colony commonly known as theSwan River Colony was founded in the remainder of Australia outside ofNew South Wales.[8] Most documents calling for the colony's foundation make no mention of a name, apart from its location at the "Port on the Western Coast of New Holland, at the Mouth of the River called 'Swan River', with the adjacent Territory",[9] and that a settlement should be formed "within the Territory of 'Western Australia'".[10] However, the law calling for the creation of the colony does appear to specify that it should be called "Western Australia".[11]
6 February 1832	The legal instrument required to formally appointJames Stirling governor of theColony of Western Australia was proclaimed, and this is commonly held as the date that theSwan River Colony was renamed Western Australia.[12][13]
19 February 1836	The portion ofNew South Wales between132° east and141° east, and south of26° south, was made theProvince of South Australia.[14] The actual landing and proclamation occurred on 28 December 1836.[15] Its border with New South Wales south of theMurray River would be erroneously surveyed roughly 3.6 kilometres (2.2 mi) west of 141° east, and the resulting disputes with the colonies and, later, states that share that border would not be fully resolved until 1914.[16]
15 June 1839	Theislands of New Zealand were annexed toNew South Wales.[17][18] The action was proclaimed on 14 January 1840.[19]
16 November 1840	TheColony of New Zealand was chartered and split fromNew South Wales.[20][21]
26 September 1844	Norfolk Island was transferred fromNew South Wales toVan Diemen's Land.[22]
17 February 1846	The half ofNew South Wales north of26° south was made theColony of North Australia.[23][24][25]
28 December 1847	Following a change in government in the United Kingdom,North Australia was merged back in toNew South Wales.[23][25] This is the dateQueen Victoria revoked theletters patent establishing North Australia, but it was not proclaimed in Australia until 16 January 1849.
1 July 1851	The portion ofNew South Wales south of theMurray River and a line from the headwaters of the river toCape Howe was made theColony of Victoria.[26]
1 January 1856	Van Diemen's Land was renamedTasmania, as a way to get away from its past as a penal colony.[27]
1 November 1856	Norfolk Island was split fromTasmania, becoming its own colony.[28] Some sources say this occurred the previous day,[29] but the Norfolk Island Act 1913 states it was on this day.
6 June 1859	The portion ofNew South Wales north of29° south, theDumaresq andMacintyre Rivers, and several mountain ridges, and east of141° east, was made theColony of Queensland.[30]
10 October 1861	The portion ofNew South Wales west ofSouth Australia was transferred to South Australia by letters patent. The act of parliament was passed on 22 July 1861.[31]
13 March 1862	The portion ofNew South Wales north ofSouth Australia and east of138° east was transferred toQueensland.[32]
6 July 1863	The region ofNew South Wales north ofSouth Australia was transferred to South Australia.[33]
30 May 1872	All islands lying within 60 miles (97 km) ofQueensland were annexed to the colony by letters patent.[34] This was done primarily to incorporate theTorres Strait Islands, which were starting to be claimed byNew South Wales. It is unknown which specific islands may have already been considered part of Queensland, and the map included with the letters patent contained errors, such as includingMelville Island in Queensland.[35]	too vague to map
21 July 1879	TheTorres Strait Islands were specifically annexed toQueensland.[34][35]
17 June 1880	Macquarie Island was made a constituent part of theColony of Tasmania through Letters Patent for the Governor of Tasmania.[36]
4 April 1883	Queensland claimed southeastNew Guinea as a dependency, though the British government rejected the claim.[37]
6 November 1884	TheBritish Empire declared southeastNew Guinea as aprotectorate, removing it from immediateQueensland control, though the colony still largely administered it.[38]

Date	Event	Map
1 January 1901	Six colonies of the United Kingdomformed the Commonwealth of Australia:[39] TheColony of New South Wales, becoming the state ofNew South Wales TheColony of Queensland, becoming the state ofQueensland TheProvince of South Australia, becoming the state ofSouth Australia TheColony of Tasmania, becoming the state ofTasmania TheColony of Victoria, becoming the state ofVictoria TheColony of Western Australia, becoming the state ofWestern Australia Parliament met inMelbourne until the federal capital could be built.[40]
1 September 1906	British New Guinea was transferred from the United Kingdom, becoming theTerritory of Papua.[41][42]
1 January 1911	TheFederal Capital Territory was split fromNew South Wales,[43][44] and theNorthern Territory was split fromSouth Australia.[45][46] While the acts creating it use the term "Territory for the Seat of Government", legislation and proclamations immediately began using the term "Federal Capital Territory."[47]
1 July 1914	Norfolk Island was transferred from the United Kingdom, becoming the Territory of Norfolk Island.[28][48]
4 September 1915	A small peninsula alongJervis Bay was ceded to theFederal Capital Territory byNew South Wales.[49][50]
17 December 1920	TheLeague of Nationsmandated the formerGerman New Guinea to Australia as theTerritory of New Guinea[51][52] and theMandate of Nauru,[53][54] withNew Zealand and the United Kingdom as co-trustees of Nauru.[55]
1 February 1927	TheNorthern Territory was split at20° south into the territories ofCentral Australia andNorth Australia.[56][57]
9 May 1927	Parliament began meeting inCanberra, formally moving the capital there fromMelbourne.[58][59]
12 June 1931	The territories of Central Australia and North Australia were merged to become theNorthern Territory.[60][61]
10 May 1934	TheAshmore and Cartier Islands were transferred from the United Kingdom and became the Territory of Ashmore and Cartier Islands. A Britishorder-in-council dated 23 July 1931 had stated that the islands would be placed under the authority of the Commonwealth of Australia when Australia passed legislation to accept them.[62][63]
24 August 1936	The United Kingdom transferred the portion of its claim toAntarctica between45° east and136° east, and142° east and160° east, to Australia, where it became theAustralian Antarctic Territory.[64][65]
29 July 1938	TheTerritory of Ashmore and Cartier Islands was annexed to theNorthern Territory.[66] The Federal Capital Territory was renamed theAustralian Capital Territory.[67]
26 August 1942	TheMandate of Nauru wascaptured by Japan.[68]
14 September 1945	The Japanese garrison in theMandate of Nauru surrendered.[68]
13 December 1946	TheTerritory of New Guinea was reconstituted as aUnited Nations trust territory.[69]
1 November 1947	TheMandate of Nauru was reconstituted as the United NationsTrust Territory of Nauru.[69]
26 December 1947	Heard Island and McDonald Islands were transferred from the United Kingdom. The receipt was confirmed in letters exchanged on 19 December 1950.[70]
1 July 1949	TheTerritory of New Guinea andTerritory of Papua were merged into theTerritory of Papua and New Guinea, mainly for administrative purposes; the act makes it clear that the identities of New Guinea as aUnited Nations Trust Territory and Papua as a possession ofthe Crown remain intact.[71][72]
24 April 1953	Heard Island and McDonald Islands were formally declared the Territory of Heard Island and McDonald Islands.[73]
23 November 1955	TheCocos (Keeling) Islands were transferred by the United Kingdom from theColony of Singapore, becoming the Territory of the Cocos (Keeling) Islands.[74][75]
1 October 1958	Christmas Island was transferred by the United Kingdom from theColony of Singapore, becoming the Territory of Christmas Island.[76][77]
31 January 1968	TheTrust Territory of Naurubecame independent as theRepublic of Nauru.[78][79]
30 September 1969	TheCoral Sea Islands Territory was created fromQueensland.[80]
27 December 1971	TheTerritory of Papua and New Guinea was renamed Papua New Guinea.[81]
31 December 1973	The peninsula alongJervis Bay belonging to theAustralian Capital Territory was formally named theJervis Bay Territory; at this time, it was still considered part of the ACT.[82]	no change to map
11 September 1975	TheRepublic of the North Solomons declared the independence of the region surroundingBougainville Island inPapua New Guinea.[83]
16 September 1975	Papua New Guineabecame independent as theIndependent State of Papua New Guinea,[84] rendering the dispute with theRepublic of the North Solomons moot.
1 July 1978	TheAshmore and Cartier Islands were split from theNorthern Territory, becoming the Territory of Ashmore and Cartier Islands.[85]
3 March 1986	TheAustralia Act 1986 made Australia completely independent of theUnited Kingdom.[86]	no change to map
11 May 1989	Jervis Bay Territory was split from theAustralian Capital Territory to become its own territory.[87]
7 July 1997	Elizabeth Reef andMiddleton Reef were transferred fromNew South Wales to theCoral Sea Islands Territory.[88]

In September 2022, it was announced the border between theAustralian Capital Territory andNew South Wales would change for the first time since it was created in 1911.^[89] ACT chief ministerAndrew Barr said NSW premierDominic Perrottet had agreed to a proposed border change for 330 hectares of land.^[90]

• Northern Territory borders
• Proposals for new Australian states
• Queensland borders
• South Australian borders
• States and territories of Australia
• Western Australian borders

• States of Australia – Statoids.com
• The Australian Institute of Aboriginal and Torres Strait Islander Studies provides amap of estimated territorial boundaries of the various First Nations of Australia

• States and territories of Australia
• Territorial evolution by country
• Borders of Australia

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