Politically, they are divided between the Federated States of Micronesia (FSM) in the central and eastern parts of the group, and Palau at the extreme western end.

[3] Most of the islands are made up of low, flat coral atolls, but there are some that rise high above sea level.

There are also a significant number of inhabitants who belong to non-indigenous ethnic groups and speak other languages, including Filipinos and Japanese.

Besides the ordinary shell money, there is a sort of stone coinage, consisting of huge calcite or limestone discs or wheels from 6 inches to 12 feet in diameter, and weighing up to nearly 5 tons.

The stones, which are rather tokens than money, do not circulate, but are piled up round about the chief's treasure-house, and appear to be regarded as public property.

[14][15][16] The first contact that European explorers had with the Caroline islands was in 1525, when a summer storm carried the Portuguese navigators Diogo da Rocha and Gomes de Sequeira eastward from the Moluccas (by way of Celebes).

About 8 months later, on 1 January 1528, the explorer Álvaro de Saavedra Cerón claimed possession of the Ulithi Islands on behalf of the king of Spain.

He named them the Islands of the Kings (Spanish: Islas de los Reyes; French: Îles des Rois) after his patron and the Three Wise Men honored in the approaching Catholic feast of Epiphany.

In 1565, the islands were briefly visited by the first governor-general of the Philippines, Miguel Lopez de Legazpi (in office from 1565 to 1572).

[21] Such vessels—from Britain, the United States, Australia and elsewhere—came for water, wood, and food and, sometimes, for men willing to serve as crewmen on the vessels.

In 1920, after World War I, Japan received a League of Nations mandate to control the Caroline and Marshall Islands.

[23] During World War II, Japan operated a large base at Truk Lagoon which it used for expansion into the southeastern Pacific.

[3] In 1899, after the Spanish priests had laid the foundations of the mission, the islands passed by purchase into the hands of Germany.

As a result, many people stopped attending church and sending their children to school, and the mission's fortunes suffered.

In response, the Propaganda Fide decided on 7 November 1904 to replace the Spanish Capuchins with German missionaries, and on 18 December 1905 to erect a single Apostolic prefecture in place of the two separate missions.

[3] In 1906, 24 missionaries (12 Fathers and 12 Brothers) were working in thirteen stations, and several Sisters of St. Francis left Luxembourg to take charge of the ten primary schools, in which a total of 262 children were enrolled.

On 1 July 1905, the United States sent a Jesuit from the Manila Observatory to the island of Yap to erect a meteorological station there, and appointed the Capuchin Father Callistus as its director.

[24] Campnosperma brevipetiolatum was first named and classified by the German botanist Georg Volkens while carrying out research on Yap.

[25][26] Crinum bakeri is endemic to the Caroline and Marshall Islands, and was first described by Karl Moritz Schumann in 1887.