The island largely consists of dense jungle and mountains, reaching its highest point at Mt. Kinabalu (13,455 ft/4,101 m) in Sabah. Much of the terrain is virtually impassable, and large areas are unexplored. Many of the rivers are navigable to small craft, however, and provide access into the interior. The largest rivers are the Kapuas in the west and the Barito in the south. The coastal area is generally swampy and fringed with mangrove forests. Banjarmasin, Pontianak, Balikpapan, Tarakan, Kuching, Bandar Seri Begawan, and Sandakan are leading ports. The climate is tropical, i.e., hot and humid; annual rainfall averages more than 100 in. (254 cm), and there is a prolonged monsoon (generally from November to May). The fauna is roughly similar to that of Sumatra and includes the elephant, deer, orangutan, gibbon, Malay bear, and crocodile, and many varieties of snakes. Rhinoceroses, once numerous, have been extensively hunted and are now almost extinct.
The island is one of the most sparsely populated regions in the world. The two major ethnic groups are the Dyaks and the coastal Malays. Kalimantan was also a center for Chinese settlement and has a number of immigrants resettled during the second half of the 20th cent. from overcrowded areas of Indonesia, particularly Madura.
Kalimantan contains Indonesia's greatest expanse of tropical rain forests, including valuable stands of camphor, sandalwood, and ironwood, and many palms. The thick jungle and myriad insects tend to discourage large-scale agriculture, but rice, sago, tobacco, millet, coconuts, pepper, sweet potatoes, sugarcane, coffee, and rubber are grown. In 1983, over 13,000 sq mi (20,917 sq km) of rain forest were destroyed by fire, causing enormous damage to the ecosystem, and immigration from other, heavily populated parts of Indonesia, combined with illegal logging, has resulted in increasing deforestation, threatening the orangutan, the pygmy elephant, and other species. Kalimantan contains some of Indonesia's most productive oil fields (discovered in 1888). Coal has been mined there for more than a century, and gold since earliest times. In 1995 one of the richest gold deposits in the world was discovered in NE Kalimantan. Other mineral resources include industrial diamonds, bauxite, and extensive reserves of low-grade iron ore, which are, however, little exploited.
Borneo was visited by the Portuguese in 1521, and shortly thereafter by the Spanish, who established trade relations with the island. The Dutch arrived in the early 1600s, and the English c.1665. Dutch influence was established on the west coast in the early 1800s and was gradually extended to the south and east. The British adventurer James Brooke took the north edge of the island in the 1840s, and what is now Sabah was declared a British protectorate in 1882, Sarawak and Brunei in 1888. The final boundaries were defined in 1905. In World War II the island was held by the Japanese from 1942 to 1945. Dutch Borneo became part of the republic of Indonesia in 1950. The union of Sabah and Sarawak with Malaya in the Federation of Malaysia in 1963 was resented by Indonesians. Indonesian guerrilla raids against both areas, begun in 1964, continued sporadically until Aug., 1966. The sultanate of Brunei became fully independent in 1984. The resettlement of non-Dyak Indonesians in Kalimantan has led to recurrent violence against the settlers by Dyaks.
Island, Malay Archipelago. Bounded by the South China Sea, the Sulu and Celebes seas, the Makassar Strait, and the Java Sea, it is the third largest island in the world, measuring about 292,000 sq mi (755,000 sq km). The northern part includes the Malaysian states of Sabah and Sarawak and the sultanate of Brunei; the southern section (Kalimantan) forms part of Indonesia. Borneo is mountainous and largely covered in dense rainforest; its highest point is Mount Kinabalu, at 13,455 ft (4,101 m). Much of it is drained by navigable rivers, including the Rajang, which are the principal lifelines of trade and commerce. It is mentioned in Ptolemy's Guide to Geography (circa AD 150); Roman trade beads give evidence of an earlier civilization. Brahman and Buddhist images in the Gupta style indicate the influence of Indians who apparently arrived in the 5th century. With the arrival of Islam in the 16th century, various Muslim kingdoms were founded, some of which owed allegiance to Java. Around the same time, the Portuguese, followed by the Spanish, set up trading stations. In the early 17th century the Dutch broke the Portuguese-Spanish monopoly, but they in turn had to deal with newly established British interests. After World War II, Sarawak and North Borneo (later Sabah) became British crown colonies. Strong nationalist sentiment emerged in Dutch Borneo, and sovereignty passed to Indonesia in 1949. The British relinquished Sabah and Sarawak to the Malaysian federation in 1963, while Brunei became independent in 1984.
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Borneo is the third largest island in the world and is located at the centre of Maritime Southeast Asia. Administratively, this island is divided between Indonesia, Malaysia and Brunei. Indonesians refer to the island as "Kalimantan." However, for people outside of Indonesia, "Kalimantan" refers to the area that Indonesia occupies on the island of Borneo. Malaysia's region of Borneo is called East Malaysia or Malaysian Borneo. The independent nation of Brunei occupies the remainder of the island. Brunei is the wealthiest nation in the island of Borneo.
To the west of Borneo
are the Malay Peninsula and Sumatra. To the south is Java. To the east is the island of Sulawesi (Celebes). To the northeast is the Philippines.
Borneo's highest point is Mount Kinabalu in Sabah, Malaysia, with an elevation of 4,095 m (13,435 ft) above sea level. This makes it the world's third highest island.
The largest river systems are the Kapuas River, with approximately the longest river in Indonesia, the Rajang River in Sarawak with some the longest river in Malaysia, the Barito River about long and the Mahakam River about long.
Borneo is also known for its extensive cave systems. Clearwater Cave has one of the world's longest underwater rivers. Deer Cave, thought to be the largest cave passage in the world, is home to over three million bats and guano accumulated to over high.
In the 15th century, the Majapahit rule exerted its influence in Borneo. Princess Junjung Buih, the queen of the Hindu kingdom of Negara Dipa (situated in Candi Agung area of Amuntai) married a Javanese prince, Prince Suryanata, and together they ruled the kingdom which is a tributary to the Majapahit Empire (1365). In this way, it became a part of Nusantara. Along the way, the power of Negara Dipa weakened and was replaced by the new court of Negara Daha. When Prince Samudra (Prince Suriansyah) of Negara Daha converted to Islam and formed the Islamic kingdom of Banjar, it inherited some of the areas previously ruled by the Hindu kingdom of Negara Daha.
The Brunei Sultanate during its golden age from the 15th to 17th centuries ruled a large part of northern Borneo. In 1703 (other sources say 1658), the Sultanate of Sulu received North Borneo from the Sultan of Brunei, after Sulu sent aid against a rebellion in Brunei. During the 1450s, Shari'ful Hashem Syed Abu Bakr, an Arab born in Johor, arrived in Sulu from Malacca. In 1457, he founded the Sultanate of Sulu; he then renamed himself "Paduka Maulana Mahasari Sharif Sultan Hashem Abu Bakr". Subsequently HM Sultan Jamalul Ahlam Kiram (1863-1881) the 29th reigning Sultan of Sulu leased North Borneo in 1878 to Gustavus Baron de Overbeck & Alfred Dent representing the British North Borneo Company
in what is now Sabah part of Malaysia. The company also exerted control on inland territories that were inhabited by numerous tribes. In the 19th Century coastal areas ruled by the Brunei Sultanate in the west of the island were gradually taken by the Brooke dynasty. 
By the 18th century, the area from Sambas to Berau were tributaries to the Banjar Kingdom, but this eventually shrunk to the size of what is now South Kalimantan as a result of agreements with the Dutch. In the Karang Intan Agreement during the reign of Prince Nata Dilaga (Susuhunan Nata Alam) (1808-1825), the Banjar Kingdom gave up its territories to the Dutch Indies which included Bulungan, Kutai, Pasir, Pagatan and Kotawaringin. Other territories given up to the Dutch Indies were Landak, Sambas, Sintang and Sukadana.
In the early 19th century, British and Dutch governments signed the Anglo-Dutch Treaty of 1824 to exchange trading ports under their controls and assert spheres of influences, in which indirectly set apart the two parts of Borneo into British and Dutch controlled areas. China has had historical trading links with the inhabitants of the island. Some of the Chinese beads and wares found their way deep into the interior of Borneo.
Moreover in the 19th century, the Dutch admitted the founding of district kingdoms with native leaders who were under the power of the Dutch (Indirect Bestuur). The Dutch assign a resident to head their rule over Kalimantan. List of the residents and governors of Kalimantan:
Since 1938, Dutch-Borneo (Kalimantan) was one administrative territory under a governor (Governor Haga) whose seat was in Banjarmasin. In 1957 following the independence of Indonesia, Kalimantan was divided into 3 provinces which is South Kalimantan, East Kalimantan and West Kalimantan. The province of Central Kalimantan separated from South Kalimantan to have their own territory in 1958.
During the Second World War, Japanese forces gained control of Borneo (1941–45). They decimated many local populations and Malay intellectuals, including the elimination of the Malay Sultanate of Sambas in Kalimantan
Borneo was the main site of the confrontation between Indonesia and Malaysia between 1962 and 1966, as well as the communist revolts to gain control of the whole area. Before the formation of Malaysian Federation, the Philippines claimed that the Malaysian state of Sabah in north Borneo is within their territorial rights based on historical facts of the Sultanate of Sulu's leasing agreement with the North Borneo Company, is presently an unresolved claim against Malaysia. Several other territorial claims such as Sipadan were resolved at The Hague international courts.
Borneo is very rich in biodiversity compared to many other areas (MacKinnon et al. 1998). There are about 15,000 species of flowering plants with 3,000 species of trees (267 species are dipterocarps), 221 species of terrestrial mammals and 420 species of resident birds in Borneo (MacKinnon et al. 1998). It is also the centre of evolution and radiation of many endemic species of plants and animals. The remaining Borneo rainforest is the only natural habitat for the endangered Bornean Orangutan. It is also an important refuge for many endemic forest species, as the Asian Elephant, the Sumatran Rhinoceros, the Bornean Clouded Leopard, and the Dayak Fruit Bat.
The World Wildlife Fund divides the island into seven distinct ecoregions. The Borneo lowland rain forests cover most of the island, with an area of . Other lowland ecoregions are the Borneo peat swamp forests, the Kerangas or Sundaland heath forests, the Southwest Borneo freshwater swamp forests, and the Sunda Shelf mangroves. The Borneo mountain rain forests lie in the central highlands of the island, above the elevation. The highest elevations of Mount Kinabalu are home to the Kinabalu mountain alpine meadow, an alpine shrubland notable for its numerous endemic species, including many orchids.
The island historically had extensive rainforest cover, but the area shrank rapidly due to heavy logging for the needs of the Malaysian plywood industry. Two forestry researchers of Sepilok Research Centre, Sandakan, Sabah in the early 80's indentified four fast-growing hardwoods and a breakthrough on seed collection and handling of Acacia mangium and Gmelina arborea, a fast growing tropical trees were planted on huge track of formerly logged and deforested areas primarily in the northern part of Borneo Island. One half of the annual tropical timber acquisition of the whole world comes from Borneo. Furthermore, Palm oil plantations are rapidly encroaching on the last remnants of primary rainforest. The rainforest was also greatly destroyed due to the forest fires in 1997 to 1998 which were started by people and coincided with an exceptional drought season of El Niño. During the great fire, hotspots could be seen on satellite images and a haze was created that affected Brunei, Malaysia, Indonesia and Singapore.
In order to combat overpopulation and AIDS in Java, the Indonesian government started a massive transmigration (transmigrasi) of poor farmers and landless peasants into Borneo in the 70's and 80's, to farm the logged areas, albeit with little success as the fertility of the land has been removed with the trees and what soil remains is washed away in tropical downpours.
There are over 30 Dayak sub-ethnic groups living in Borneo, making the population of this island one of the most varied of human social groups. The native ethnic groups are Dayak Austronesians and their languages belong to the Malayo-Polynesian language family. Some sub-ethnicities are now represented by only 30-100 individuals and are threatened with extinction. Much culture, language, ethnomusic and traditional knowledge has yet to be documented by anthropologists. Ancestral knowledge of ethnobotany
and ethnozoology
is useful in drug discovery (for example, bintangor plant for AIDS) or as future alternative food sources (such as sago starch for lactic acid production and sago maggots as a protein source).
Certain indigenous Dayak people (such as the Kayan, Kenyah, Punan Bah and Penan) living on the island have been struggling for decades for their right to preserve their environment from loggers and transmigrant settlers and colonists. Land reform is needed for future development in the face of rapid economic changes.
The type of rainforests found in Borneo include the high diversity mixed dipterocarp forest, the rare peat swamp forests and heath forest.
Researchers scouring swamps in the heart of Borneo island have discovered a venomous species of snake that can change its skin color. Scientists named their find the Kapuas mud snake, and speculated it might only occur in the Kapuas River drainage system.
World Wildlife Fund has stated that 361 animal and plant species have been discovered in Borneo since 1996, underscoring its unparalleled biodiversity.
In the 18 month period from July 2005 until December 2006, another 52 new species were found.
