Nauru ( or ; Naoero), officially the Republic of Nauru (Repubrikin Naoero) and formerly known as Pleasant Island, is an island country in Micronesia, a subregion of Oceania, in the Central Pacific. Its nearest neighbour is Banaba Island in Kiribati, 300 km to the east. It further lies northwest of Tuvalu, north of the Solomon Islands, east-northeast of Papua New Guinea, southeast of the Federated States of Micronesia and south of the Marshall Islands. With only a 21 km2 area, Nauru is the third-smallest state on the list of countries and dependencies by area behind Vatican City and Monaco, making it the smallest state in the South Pacific Ocean, the smallest island state, and the smallest republic. Its population is, making it the third smallest on the list of countries and dependencies by population, after the Vatican and Tuvalu.
Settled by people from Micronesia and Polynesia c. 1000 BC, Nauru was annexed and claimed as a colony by the German Empire in the late 19th century. After World War I, Nauru became a League of Nations mandate administered by Australia, New Zealand and the United Kingdom. During World War II, Nauru was occupied by Japanese troops, who were bypassed by the Allied advance across the Pacific. After the war ended, the country entered into United Nations trusteeship. Nauru gained its independence in 1968, and became a member of the Pacific Community (SPC) in 1969.
Nauru is a phosphate-rock island with rich deposits near the surface, which allowed easy strip mining operations. It has some remaining phosphate resources which,, are not economically viable for extraction. When the phosphate reserves were exhausted, and the island's environment had been seriously harmed by mining, the trust that had been established to manage the island's wealth diminished in value. To earn income, Nauru briefly became a tax haven and illegal money laundering centre. From 2001 to 2008, and again from 2012, it accepted aid from the Australian Government in exchange for hosting the Nauru Regional Processing Centre, an offshore Australian immigration detention facility. As a result of heavy dependence on Australia, many sources have identified Nauru as a client state of Australia.
Nauru was first inhabited by Micronesians and Polynesians at least 3,000 years ago. There were traditionally 12 clans or tribes on Nauru, which are represented in the twelve-pointed star on the country's flag. Traditionally, Nauruans traced their descent matrilineally. Inhabitants practised aquaculture: they caught juvenile ibija fish, acclimatised them to fresh water, and raised them in the Buada Lagoon, providing a reliable source of food. The other locally grown components of their diet included coconuts and pandanus fruit. The name "Nauru" may derive from the Nauruan word Anáoero, which means 'I go to the beach'.
The British sea captain John Fearn, a whale hunter, became the first Westerner to visit Nauru, in 1798, calling it "Pleasant Island". From around 1830, Nauruans had contact with Europeans from whaling ships and traders who replenished their supplies, particularly fresh water, at Nauru.
Around this time, deserters from European ships began to live on the island. The islanders traded food for alcoholic palm wine and firearms. The firearms were used during the 10-year Nauruan Tribal War that began in 1878.
After an agreement with Great Britain, Nauru was annexed by Germany in 1888 and incorporated into Germany's Marshall Islands Protectorate for administrative purposes. The arrival of the Germans ended the civil war, and kings were established as rulers of the island. The most widely known of these was King Auweyida. Christian missionaries from the Gilbert Islands arrived in 1888. The German settlers called the island "Nawodo" or "Onawero". The Germans ruled Nauru for almost three decades. Robert Rasch, a German trader who married a Nauruan woman, was the first administrator, appointed in 1890.
Phosphate was discovered on Nauru in 1900 by the prospector Albert Fuller Ellis. The Pacific Phosphate Company began to exploit the reserves in 1906 by agreement with Germany, exporting its first shipment in 1907. In 1914, following the outbreak of World War I, Nauru was captured by Australian troops. In 1919 it was agreed by the Allied and Associated Powers that His Britannic Majesty should be the administering authority under a League of Nations mandate. The Nauru Island Agreement forged in 1919 between the governments of the United Kingdom, Australia, and New Zealand provided for the administration of the island and for extraction of the phosphate deposits by an intergovernmental British Phosphate Commission (BPC). The terms of the League of Nations mandate were drawn up in 1920.
The island experienced an influenza epidemic in 1920, with a mortality rate of 18 per cent among native Nauruans.
In 1923, the League of Nations gave Australia a trustee mandate over Nauru, with the United Kingdom and New Zealand as co-trustees. On 6 and 7 December 1940, the German auxiliary cruisers Komet and Orion sank five supply ships in the vicinity of Nauru. Komet then shelled Nauru's phosphate mining areas, oil storage depots, and the shiploading cantilever.