Australia

The earliest known life forms on Earth may be as old as 4.1 billion years (or Ga) according to biologically fractionated graphite inside a single zircon grain in the Jack Hills range of Australia. The earliest evidence of life found in a stratigraphic unit, not just a single mineral grain, is the 3.7 Ga metasedimentary rocks containing graphite from the Isua Supracrustal Belt in Greenland. The earliest direct known life on Earth are stromatolite fossils which have been found in 3.480-billion-year-old geyserite uncovered in the Dresser Formation of the Pilbara Craton of Western Australia. Various microfossils of microorganisms have been found in 3.4 Ga rocks, including 3.465-billion-year-old Apex chert rocks from the same Australian craton region, and in 3.42 Ga hydrothermal vent precipitates from Barberton, South Africa. Much later in the geologic record, likely starting in 1.73 Ga, preserved molecular compounds of biologic origin are indicative of aerobic life. Therefore, the earliest time for the origin of life on Earth is at least 3.5 billion years ago and possibly as early as 4.1 billion years ago — not long after the oceans formed 4.5 billion years ago and after the formation of the Earth 4.54 billion years ago.

A dominion was any one of several largely self-governing countries that remained, especially in the first half of the 20th century, under the British Crown as parts of the British Empire and then the British Commonwealth of Nations. The list of dominions as at 1926 included Australia, Canada, the Irish Free State, New Zealand, Newfoundland, and South Africa; later Ceylon (now Sri Lanka), India, and Pakistan also became dominions for short periods. Progressing from colonies, their degrees of colonial self-governance increased (and, in one case, decreased) but did so unevenly over the late 19th century through the 1930s. In the years following the Second World War, the British Empire was refashioned into the more modern (and more post-colonial) Commonwealth of Nations (after which the former dominions were often referred to as the Old Commonwealth). By the time this transition was formally finalised, in 1949, the old dominions had become more autonomous and independent nation states, each in their own right, either as a Commonwealth republic or a Commonwealth realm.

In 1925, the government of the United Kingdom created the Dominions Office from the Colonial Office, although for the next five years they shared the same secretary in charge of both offices. "Dominion status" was first accorded to Australia, Canada, the Irish Free State, New Zealand, Newfoundland, and South Africa at the 1926 Imperial Conference through the Balfour Declaration of 1926, recognising Great Britain and the Dominions as "autonomous communities within the British Empire, equal in status, in no way subordinate one to another in any aspect of their domestic or external affairs, though united by a common allegiance to the Crown and freely associated as members of the British Commonwealth of Nations". Their full legislative independence was subsequently confirmed in the Statute of Westminster 1931. In the 1920s and 1930s, they began to represent themselves in international bodies, in treaty making, and in foreign capitals. Vestiges of empire and colonial rule lasted in some dominions late into the 20th century and indeed still exist today.

English is a West Germanic language that emerged in early medieval England and has since become a global lingua franca. The namesake of the language is the Angles, one of the Germanic peoples who migrated to Britain after the end of Roman rule. English is the most spoken language in the world, primarily due to the global influences of the former British Empire (succeeded by the Commonwealth of Nations) and the United States. It is the most widely learned second language in the world, with more second-language speakers than native speakers. However, English is only the third-most spoken native language, after Mandarin Chinese and Spanish.

English is either the official language, or one of the official languages, in 57 sovereign states and 30 dependent territories, making it the most geographically widespread language in the world. In the United Kingdom, the United States, Australia, and New Zealand, it is the dominant language for historical reasons without being explicitly defined by law. It is a co-official language of the United Nations, the European Union, and many other international and regional organisations. It has also become the de facto lingua franca of diplomacy, science, technology, international trade, logistics, tourism, aviation, entertainment, and the Internet. Ethnologue estimated that there were over 1.4 billion speakers worldwide as of 2021.

The Allies, formally referred to as the United Nations from 1942, were an international military coalition formed during World War II (1939–1945) to oppose the Axis powers. Its principal members were the "Big Four" – the United Kingdom, Soviet Union, United States, and China.

Membership in the Allies varied during the course of the war. When the conflict broke out on 1 September 1939, the Allied coalition consisted of the United Kingdom, France, and Poland, as well as their respective dependencies, such as British India. They were joined by the independent dominions of the British Commonwealth: Canada, Australia, New Zealand and South Africa. Consequently, the initial alliance resembled that of the First World War. As Axis forces began invading northern Europe and the Balkans, the Allies added the Netherlands, Belgium, Norway, Greece, and Yugoslavia. The Soviet Union, which initially had a nonaggression pact with Germany and participated in its invasion of Poland, joined the Allies after the German invasion of the Soviet Union in June 1941. The United States, while providing some material support to European Allies since September 1940, remained formally neutral until the Japanese attack on Pearl Harbor in December 1941, after which it declared war and officially joined the Allies. China had already been at war with Japan since 1937, and formally joined the Allies in December 1941.

New Zealand is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island (Te Ika-a-Māui) and the South Island (Te Waipounamu)—and over 600 smaller islands. It is the sixth-largest island country by area and lies east of Australia across the Tasman Sea and south of the islands of New Caledonia, Fiji, and Tonga. The country's varied topography and sharp mountain peaks, including the Southern Alps (Kā Tiritiri o te Moana), owe much to tectonic uplift and volcanic eruptions. New Zealand's capital city is Wellington, and its most populous city is Auckland.

The islands of New Zealand were the last large habitable land to be settled by humans. Between about 1280 and 1350, Polynesians began to settle in the islands and subsequently developed a distinctive Māori culture. In 1642, the Dutch explorer Abel Tasman became the first European to sight and record New Zealand. In 1769 the British explorer Captain James Cook became the first European to set foot on and map New Zealand. In 1840, representatives of the United Kingdom and Māori chiefs signed the Treaty of Waitangi, which paved the way for Britain's declaration of sovereignty later that year and the establishment of the Crown Colony of New Zealand in 1841. Subsequently, a series of conflicts between the colonial government and Māori tribes resulted in the alienation and confiscation of large amounts of Māori land. New Zealand became a dominion in 1907; it gained full statutory independence in 1947, retaining the monarch as head of state. Today, the majority of New Zealand's population of around 5.3 million is of European descent; the indigenous Māori are the largest minority, followed by Asians and Pasifika. Reflecting this, New Zealand's culture mainly derives from Māori and early British settlers but has recently broadened from increased immigration. The official languages are English, Māori, and New Zealand Sign Language, with the local dialect of English being dominant.

Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian and Pacific oceans. Comprising over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guinea, Indonesia is the world's largest archipelagic state and the 14th-largest country by area, at 1,904,569 square kilometres (735,358 square miles). With over 280 million people, Indonesia is the world's fourth-most-populous country and the most populous Muslim-majority country. Java, the world's most populous island, is home to more than half of the country's population.

Indonesia operates as a presidential republic with an elected legislature and consists of 38 provinces, nine of which have special autonomous status. Jakarta, the largest city, is the world's second-most-populous urban area. Indonesia shares land borders with Papua New Guinea, Timor-Leste, and East Malaysia, as well as maritime borders with Singapore, Peninsular Malaysia, Vietnam, Thailand, the Philippines, Australia, Palau, and India. Despite its large population and densely populated regions, Indonesia has vast areas of wilderness that support one of the world's highest levels of biodiversity.

Today the term South Seas, or South Sea, most commonly refers to the portion of the Pacific Ocean south of the equator. The term South Sea may also be used synonymously for Oceania, or even more narrowly for Polynesia or the Polynesian Triangle, an area bounded by the Hawaiian Islands, New Zealand and Easter Island. Pacific Islanders are commonly referred to as South Sea Islanders, particularly in Australia.

The term was coined as Mar de Sur, or "South Sea",  by Spanish conquistador Vasco Núñez de Balboa in 1513 as he it encountered on the southern coast of the Isthmus of Panama and it was applied to the entirety today's Pacific Ocean. In 1520, Ferdinand Magellan named the same ocean the Pacific Ocean, and over time Magellan's name became more well-known.

An island is a landmass (smaller than a continent) that is surrounded by water. Many island countries are spread over an archipelago, as is the case with Indonesia, Japan, and the Philippines—these countries consist of thousands of islands. Others consist of a single island, such as Barbados, Dominica, and Nauru; a main island and some smaller islands, such as Cuba, Iceland, and Sri Lanka; a part of an island, such as Brunei, the Dominican Republic, East Timor, and the Republic of Ireland; or one main island but also sharing borders in other islands, such as the United Kingdom (Great Britain and a part of Ireland).

The list also includes two states in free association with New Zealand, the Cook Islands and Niue, as well as two states with limited diplomatic recognition which have de facto control over territories entirely on the islands, Northern Cyprus and Taiwan. In total, 50 island countries have been included in the lists.

The Antarctic Treaty and related agreements, collectively known as the Antarctic Treaty System (ATS), regulate international relations with respect to Antarctica, Earth's only continent without a native human population. It was the first arms control agreement established during the Cold War, designating the continent as a scientific preserve, establishing freedom of scientific investigation, and banning military activity; for the purposes of the treaty system, Antarctica is defined as all the land and ice shelves south of 60°S latitude. Since September 2004, the Antarctic Treaty Secretariat, which implements the treaty system, is headquartered in Buenos Aires, Argentina.

The main treaty was opened for signature on 1 December 1959, and officially entered into force on 23 June 1961. The original signatories were the 12 countries active in Antarctica during the International Geophysical Year (IGY) of 1957–58: Argentina, Australia, Belgium, Chile, France, Japan, New Zealand, Norway, South Africa, the Soviet Union, the United Kingdom, and the United States. These countries had established over 55 Antarctic research stations for the IGY, and the subsequent promulgation of the treaty was seen as a diplomatic expression of the operational and scientific cooperation that had been achieved. As of 2024, the treaty has 58 parties.

A jurisdiction is the legal authority of a court, government, or other entity to make and enforce laws within a defined area.

Each state in a federation—such as Australia, Germany, and the United States—forms a separate jurisdiction. Certain laws, however, may be uniform across the constituent states and enforced by federal courts, resulting in a single jurisdiction for those purposes.