Mainland Australia in the context of Australian Colonies

Afro-Eurasia (also Afroeurasia and Eurafrasia) is a landmass comprising the continents of Africa, Asia, and Europe. The terms are compound words of the names of its constituent parts. Afro-Eurasia has also been called the "Old World", in contrast to the "New World" referring to the Americas.

Afro-Eurasia encompasses 85,135,000 km (32,871,000 sq mi), 57% of the world's land area, and has a population of approximately 6.7 billion people, roughly 86% of the world population. Together with mainland Australia, they comprise the vast majority of the land in the world's Eastern Hemisphere. The Afro-Eurasian mainland is the largest and most populous contiguous landmass on Earth.

Oceania (UK: /ˌoʊsiˈɑːniə, ˌoʊʃi-, -ˈeɪn-/ OH-s(h)ee-AH-nee-ə, -⁠AY-, US: /ˌoʊʃiˈæniə, -ˈɑːn-/ OH-shee-A(H)N-ee-ə) is a geographical region including Australasia, Melanesia, Micronesia, and Polynesia. Outside of the English-speaking world, Oceania is generally considered a continent, while Mainland Australia is regarded as its continental landmass. Spanning the Eastern and Western hemispheres, at the centre of the water hemisphere, Oceania is estimated to have a land area of about 9,000,000 square kilometres (3,500,000 sq mi) and a population of around 46.3 million as of 2024. Oceania is the smallest continent in land area and the second-least populated after Antarctica.

Oceania has a diverse mix of economies from the highly developed and globally competitive financial markets of Australia, French Polynesia, Hawaii, New Caledonia, and New Zealand, which rank high in quality of life and Human Development Index, to the much less developed economies of Kiribati, Papua New Guinea, Tuvalu, Vanuatu, and Western New Guinea. The largest and most populous country in Oceania is Australia, and the largest city is Sydney. Puncak Jaya in Indonesia is the highest peak in Oceania at 4,884 m (16,024 ft).

The continent of Australia, sometimes known in technical contexts as Sahul (/səˈhuːl/), Australia-New Guinea, Australinea, or Meganesia to distinguish it from the country of Australia, is located within the Southern and Eastern hemispheres, near the Maritime Southeast Asia. The continent includes mainland Australia, Tasmania, the island of New Guinea (Papua New Guinea and Western New Guinea), the Aru Islands, the Ashmore and Cartier Islands, most of the Coral Sea Islands, and some other nearby islands. Situated in the geographical region of Oceania, more specifically in the subregion of Australasia, Australia is the smallest of the seven traditional continents.

The continent includes a continental shelf overlain by shallow seas which divide it into several landmasses—the Arafura Sea and Torres Strait between mainland Australia and New Guinea, and Bass Strait between mainland Australia and Tasmania. When sea levels were lower during the Pleistocene ice age, including the Last Glacial Maximum about 18,000 BC, they were connected by dry land into the combined landmass of Sahul. The name "Sahul" derives from the Sahul Shelf, which is a part of the continental shelf of the Australian continent. During the past 18,000 to 10,000 years, rising sea levels overflowed the lowlands and separated the continent into today's low-lying arid to semi-arid mainland and the two mountainous islands of New Guinea and Tasmania. With a total land area of 8.56 million square kilometres (3,310,000 sq mi), the Australian continent is the smallest, lowest, flattest, and second-driest continent (after Antarctica) on Earth. As the country of Australia is mostly on a single landmass, and comprises most of the continent, it is sometimes informally referred to as an island continent, surrounded by oceans.

Australia, officially the Commonwealth of Australia, is a country comprising the mainland of the Australian continent, the island of Tasmania and numerous smaller islands. It has a total area of 7,688,287 km (2,968,464 sq mi), making it the sixth-largest country in the world and the largest in Oceania. Australia is the world's flattest and driest inhabited continent. It is a megadiverse country, and its size gives it a wide variety of landscapes and climates including deserts in the interior and tropical rainforests along the coast.

The ancestors of Aboriginal Australians began arriving from Southeast Asia 50,000 to 65,000 years ago, during the Last Glacial Period. By the time of British settlement, Aboriginal Australians spoke more than 250 distinct languages and had one of the oldest living cultures in the world. Australia's written history commenced with Dutch exploration of most of the coastline in the 17th century. British colonisation began in 1788 with the establishment of the penal colony of New South Wales. By the mid-19th century, most of the continent had been explored by European settlers and five additional self-governing British colonies were established, each gaining responsible government by 1890. The colonies federated in 1901, forming the Commonwealth of Australia. This continued a process of increasing autonomy from the United Kingdom, highlighted by the Statute of Westminster Adoption Act 1942, and culminating in the Australia Acts of 1986.

Southeast Asia is the geographical southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of mainland Australia, which is part of Oceania. Southeast Asia is bordered to the north by East Asia, to the west by South Asia and the Bay of Bengal, to the east by Oceania and the Pacific Ocean, and to the south by Australia and the Indian Ocean. Apart from the British Indian Ocean Territory and two out of 26 atolls of the Maldives in South Asia, Maritime Southeast Asia is the only other subregion of Asia that lies partly within the Southern Hemisphere. Mainland Southeast Asia is entirely in the Northern Hemisphere. Timor-Leste and the southern portion of Indonesia are the parts of Southeast Asia that lie south of the equator.

The region lies near the intersection of geological plates, with both heavy seismic and volcanic activities. The Sunda plate is the main plate of the region, featuring almost all Southeast Asian countries except Myanmar, northern Thailand, northern Laos, northern Vietnam, and northern Luzon of the Philippines, while the Sunda plate only includes western Indonesia to as far east as the Indonesian province of Bali. The mountain ranges in Myanmar, Thailand, Peninsular Malaysia, and the Indonesian islands of Sumatra, Java, Bali, Lesser Sunda Islands, and Timor are part of the Alpide belt, while the islands of the Philippines and Indonesia as well as Timor-Leste are part of the Pacific Ring of Fire. Both seismic belts meet in Indonesia, causing the region to have relatively high occurrences of earthquakes and volcanic eruptions, particularly in the Philippines and Indonesia.

This is a list of sovereign states and dependent territories in the geographical region of Oceania. Although it is mostly ocean and spans many tectonic plates, Oceania is occasionally listed as one of the continents.

Most of this list follows the boundaries of geopolitical Oceania, which includes Australasia, Melanesia, Micronesia, and Polynesia. The main continental landmass of Oceania is Australia.

Tasmania (/tæzˈmeɪniə/; palawa kani: Lutruwita) is an island state of Australia. It is located 240 kilometres (150 miles) to the south of the Australian mainland, and is separated from it by the Bass Strait. The state encompasses the main island of Tasmania, the 26th-largest island in the world, and the surrounding 1000 islands. It is Australia's smallest and least populous state, with 573,479 residents as of June 2023. The state capital and largest city is Hobart, with around 40% of the population living in the Greater Hobart area. Tasmania is the most decentralised state in Australia, with the lowest proportion of its residents living within its capital city.

Tasmania's main island was first inhabited by Aboriginal peoples, who today generally identify as Palawa or Pakana. It is believed that Aboriginal Tasmanians became isolated from mainland Aboriginal groups around 11,700 years ago, when rising sea levels formed Bass Strait.

New Guinea (Tok Pisin: Niugini; Hiri Motu: Niu Gini; Indonesian: Papua, fossilized Nugini, also known as Papua or historically Irian) is the world's second-largest island, with an area of 785,753 km (303,381 sq mi). It has the third-largest remaining rainforest globally, and the highest plant biodiversity of any island. Located in Melanesia in the southwestern Pacific Ocean, the island is separated from Australia by the 150-kilometre (81-nautical-mile; 93-mile) wide Torres Strait, though both landmasses lie on the same continental shelf, and were united during episodes of low sea level in the Pleistocene glaciations as the combined landmass of Sahul. Numerous smaller islands are located to the west and east. The island's name was given by Spanish explorer Yñigo Ortiz de Retez during his maritime expedition of 1545 because of the perceived resemblance of the indigenous peoples of the island to those in the African region of Guinea.

The eastern half of the island is the major land mass of the nation of Papua New Guinea. The western half, known as Western New Guinea, forms a part of Indonesia and is organized as the provinces of Papua, Central Papua, Highland Papua, South Papua, Southwest Papua, and West Papua. The two major cities on the island are Port Moresby and Jayapura.

Bass Strait is a strait separating the island state of Tasmania from the Australian mainland (more specifically the coast of Victoria, with the exception of the land border across Boundary Islet). The strait provides the most direct waterway between the Great Australian Bight and the Tasman Sea, and is also the only maritime route into the economically prominent Port Phillip Bay.

Formed 8,000 years ago by rising sea levels at the end of the last glacial period, the strait was named after English explorer and physician George Bass (1771–1803) by European colonists.

Sahul (/səˈhuːl/), also called Sahul-land, Meganesia, Papualand and Greater Australia, was a paleocontinent that encompassed the modern-day landmasses of mainland Australia, Tasmania, New Guinea, and the Aru Islands.

Sahul was in the south-western Pacific Ocean, located approximately north to south between the Equator and the 44th parallel south and west to east between the 112th and the 152nd meridians east. Sahul was separated from Sunda to its west by the Wallacean Archipelago. At its largest, when ocean levels were at their lowest, it was approximately 10,600,000 square kilometres (4,100,000 sq mi) in size.

9°36′S 131°42′E / 9.6°S 131.7°E / -9.6; 131.7

Geologically, the Sahul Shelf (/səˈhuːl/) is a part of the continental shelf of the Australian continent, lying off the northwest coast of mainland Australia.

The states and territories are the national subdivisions and second level of government of Australia. The states are partially sovereign, administrative divisions that are self-governing polities, having ceded some sovereign rights to the federal government. They have their own constitutions, legislatures, executive governments, judiciaries and law enforcement agencies that administer and deliver public policies and programs. Territories can be autonomous and administer local policies and programs much like the states in practice, but are still legally subordinate to the federal government.

Australia has six federated states: New South Wales (including Lord Howe Island), Queensland, South Australia, Tasmania (including Macquarie Island), Victoria, and Western Australia. Australia also has ten federal territories, out of which three are internal territories: the Australian Capital Territory, the Jervis Bay Territory, and the Northern Territory on the Australian mainland; and seven are external territories: the Ashmore and Cartier Islands, the Australian Antarctic Territory, Christmas Island, the Cocos (Keeling) Islands, the Coral Sea Islands, Heard Island and McDonald Islands, and Norfolk Island that are offshore dependent territories. Every state and internal territory (except the Jervis Bay Territory) is self-governing with its own independent executive government, legislature, and judicial system, while the rest only have local government status overseen by federal departments.

New Holland (Dutch: Het Niew Holland or Nieuw-Holland) is a historical European name for mainland Australia, first encountered by Europeans in 1606, by Dutch navigator Willem Janszoon aboard Duyfken. The name was first applied to Australia in 1644 by the Dutch seafarer Abel Tasman, and for a time came to be applied in most European maps to the vaunted "Southern land" or Terra Australis even after its coastline was finally explored.

The continent of Antarctica, later named in the 1890s, was still in largely speculative form; it resumed the name Terra Australis (sometimes suffixed Non Cognita, lit. 'unknown'). Its existence had been speculated on in some maps since the 5th century, under the theory of "balancing hemispheres".

Deserts cover about 1,371,000 km (529,000 sq mi), or 18%, of the Australian mainland, but about 35% of the Australian continent receives so little rain, it is practically desert. Collectively known as the Great Australian desert, they are primarily distributed throughout the Western Plateau and interior lowlands of the country, covering areas from South West Queensland, the Far West region of New South Wales, Sunraysia in Victoria and Spencer Gulf in South Australia to the Barkly Tableland in Northern Territory and the Kimberley region in Western Australia.

By international standards, the Great Australian desert receives relatively high rates of rainfall, around 250 mm (10 in) on average, but due to the high evapotranspiration it would be correspondingly arid. No Australian weather stations situated in an arid region record less than 100 mm (3.94 in) of average annual rainfall. The deserts in the interior and south lack any significant summer rains. The desert in western Australia is well explained by the little evaporation of the cold sea current of the West Australian Current, of polar origin, which prevents significant rainfall in the interior of the continent. About 40% of Australia is covered by dunes. Australia is the driest inhabited continent, with the least fertile soils.

The eastern states of Australia are the states adjoining the east continental coastline of Australia. These are the mainland states of Victoria, New South Wales and Queensland, and the island state of Tasmania. The Australian Capital Territory and Jervis Bay Territory, while not states, are also included. On some occasions, the southern state of South Australia is also included in this grouping due to its economic ties with the eastern states.

Regardless of which definition is used, the eastern states include the great majority of the Australian population. They contain the federal capital Canberra and Australia's three largest cities Sydney, Melbourne and Brisbane (all capitals of the respective east coast states). Of the 19 Australian cities with populations over 100,000 in 2021, 16 were located in the eastern states under the restricted definition (17 if including South Australia), which includes the two non-capital cities with a population over 500,000: Gold Coast, Queensland and Newcastle, New South Wales. In terms of climate, the area is dominated by a humid subtropical zone, with some tropical (Queensland) and oceanic climate (Australian Capital Territory, Victoria, New South Wales) zones. In most situations, the eastern states are defined as those who use Australian Eastern Standard Time (AEST), and that is the definition that this article will adhere to, unless noted.

Aboriginal Australians are the various indigenous peoples of the Australian mainland and many of its islands, excluding the ethnically distinct people of the Torres Strait Islands.

Humans first migrated to Australia 50,000 to 65,000 years ago, and over time formed as many as 500 linguistic and territorial groups. In the past, Aboriginal people lived over large sections of the continental shelf. They were isolated on many of the smaller offshore islands and Tasmania when the land was inundated at the start of the Holocene inter-glacial period, about 11,700 years ago. Despite this, Aboriginal people maintained extensive networks within the continent and certain groups maintained relationships with Torres Strait Islanders and the Makassar people of modern-day Indonesia.

The Great Australian Bight is a large oceanic bight, or open bay, off the central and western portions of the southern coastline of mainland Australia.

There are two definitions for its extent—one by the International Hydrographic Organization (IHO) and another by the Australian Hydrographic Service (AHS). The bight is generally considered part of the Indian Ocean, although the AHS classifies it as part of the Southern Ocean. Its coastline is characterized by cliff faces and rocky capes, making it an ideal location for whale-watching.

The First Fleet were eleven British ships which transported a group of settlers to mainland Australia, marking the beginning of the European colonisation of Australia. It consisted of two Royal Navy vessels, three storeships and six convict transports under the command of Captain Arthur Phillip. On 13 May 1787, the ships, with over 1,400 convicts, marines, sailors, colonial officials and free settlers onboard, left Portsmouth and travelled over 24,000 kilometres (15,000 mi; 13,000 nmi) and over 250 days before arriving in Botany Bay on 18 January 1788. Governor Arthur Phillip rejected Botany Bay choosing instead Port Jackson, to the north, as the site for the new colony; they arrived there on 26 January 1788, establishing the colony of New South Wales, as a penal colony which would become the first British settlement in Australia.