Sumatra has great natural wealth; about 70% of the country's income is produced there. The island has some of Indonesia's richest oil fields, its finest coalfields, and deposits of gold and silver. Its offshore islands are known for their tin and bauxite. Most of the country's rubber is grown in Sumatra; pepper, coffee, tea, sugarcane, and oil palms are also grown on plantations. The Deli region around Medan is famous for its tobacco. Rice, corn, and root crops are raised for local consumption. Timber cut includes camphor and ebony.
Sumatra comprises eight provinces of Indonesia. It is a sparsely settled island, with principal centers at Medan and Palembang; also important are Jambi, Padang, and Bandar Laumpung. There are state universities in Jambi, Medan, Padang, Pakanbaru, and Palembang. The four largest ethnic groups are the Acehnese, Batak, Minangkabau, and coastal Malays. In the interior highlands are found the Gayo-Alas and the Rejang-Lebong groups. Islam is the predominant religion, though there are many Christians among the Batak and the Gayo-Alas. Chinese, Arabs, and Indians live on the coasts, and some 15 different languages are spoken on the island.
Sumatra had early contact with Indian civilization, and by the 7th cent. A.D. the powerful Hindu-Sumatran kingdom of Sri Vijaya (with its capital in or near Palembang) flourished under the house of Sailendra. The kingdom extended its control over a large part of Indonesia and also over the Malay Peninsula. By the 14th cent., Sumatran supremacy had waned, and the island fell under the Javanese kingdom of Majapahit. The Arabs, who may have arrived as early as the 10th cent., established the sultanate of Achin (now Aceh), which reached its height in the 17th cent. and controlled most of the island.
The first European to visit Sumatra was Marco Polo, who was there briefly c.1292. Following the Portuguese, who came in 1509, the Dutch arrived in 1596 and gradually gained control of all the native states including Achin. The British had brief control over parts of the island in the late 18th and early 19th cent. The Achinese (Acehnese) launched a rebellion in 1873 and were not subdued by the Dutch until 1904. In World War II, Japanese troops landed (Feb., 1942) in Sumatra and occupied it throughout the war.
After Indonesian independence was granted (1949), all of Sumatra was included in the new republic. Since then there has been much indigenous agitation and repeated demands for local autonomy. The Acehnese have waged occasional guerrilla warfare against the government, and in 1958 a full-scale rebellion was launched by dissident army officers. It spread to other islands before being quelled by the government. Sentiment for autonomy or independence remains strong among the Acehnese. Guerrilla attacks and demonstrations in Aceh increased in 1999 and 2000 after the end of Indonesian authority in East Timor. Indonesian legislation in 2001 granted Aceh limited local autonomy, including the right to implement Islamic law, but sentiment in favor of independence remained strong and fighting escalated. A peace pact with the rebels (Dec., 2002) only paused the conflict for a few months. In Dec., 2004, an earthquake and resulting tsunami devastated the coastal Aceh and North Sumatra. Most of Indonesia's 167,000 deaths from the event occurred on Sumatra. In Aug., 2005, a new peace accord with signed with Aceh's rebels; it led to rebel disarmament and, in 2006, the beginning of the establishment of local self-government. Aceh and North Sumatra suffered disastrous flooding from heavy rains in Dec., 2006; more than 400,000 were displaced. Earthquakes in 2007 and 2009 caused significant destruction and deaths in the area around Padang.
See F. M. Schnitger, Forgotten Kingdoms in Sumatra (1989).
Sumatra (also spelled Sumatera) is the sixth largest island in the world (approximately 470,000 km²) and is the largest island entirely in Indonesia (two larger islands, Borneo and New Guinea, are partially in Indonesia).
Srivijayan influence waned in the 11th century after it was defeated by the Chola Empire of southern India. Sumatra was then subject to conquests from Javanese kingdoms, first Singhasari and subsequently Majapahit. At the same time Islam made its way to Sumatra, spreading through contacts with Arabs and Indian traders.
By the late 13th century, the monarch of the Samudra kingdom had converted to Islam. Marco Polo visited the island in 1292 and Ibn Battuta visited twice during 1345-1346. Samudra was succeeded by the powerful Aceh Sultanate, which survived to the 20th century. With the coming of the Dutch, the many Sumatran princely states gradually fell under their control. Aceh, in the north, was the major obstacle, as the Dutch were involved in the long and costly Aceh War (1870-1905).
On December 26 2004, the western coast and islands of Sumatra, particularly Aceh province, were devastated by a nearly 15 meter high tsunami following the 9.2-magnitude Indian Ocean earthquake. The death toll surpassed 170,000 in Indonesia alone, primarily in Aceh.
In 2005 there was an 8.7 magnitude aftershock of the previous earthquake in December 2004. See 2005 Sumatran Earthquake. In addition to the subduction megathrust earthquake off the west coast, Sunda arc, the Great Sumatran Fault, a transform fault, runs the entire length of the island. The pressure on this fault increased dramatically after the December 2004 earthquake, and seismologists are afraid an earthquake is going to occur soon. The fault ends directly below the devastated city of Banda Aceh.
The longest axis of the island runs approximately 1,790 km (1,100 miles) northwest - southeast, crossing the equator near the center. At its widest point the island spans 435 km (270 miles). The interior of the island is dominated by two geographical regions: the Barisan Mountains in the west and swampy plains in the east.
To the southeast is Java, separated by the Sunda Strait. To the north is the Malay Peninsula, separated by the Straits of Malacca. To the east is Borneo, across the Karimata Strait. West of the island is the Indian Ocean.
The backbone of the island is the Barisan mountains chain, with the active volcano Mount Kerinci's 3,805 m (12,467 ft) the highest point, located at about the midpoint of the range. The volcanic activity of this region endowed the region with fertile land and beautiful sceneries, for instance around the Lake Toba. It also contains deposits of coal and gold.
To the east, big rivers carry silt from the mountain, forming the vast lowland interspersed by swamps. Even if mostly unsuitable for farming, the area is currently of great economic importance for Indonesia. It produces oil from both above and below the soil—palm oil and petroleum.
Sumatra is the largest producer of Indonesian coffee. Small-holders grow Arabica coffee (Coffea arabica) in the highlands, while Robusta (Coffea canephora) is found in the low lands. Arabica coffee from the regions of Gayo, Lintong and Sidikilang is typically processed using the Giling Basah (wet hulling) technique, which gives it a heavy body and low acidity.
Most of Sumatra used to be covered by tropical rainforest, but economic development coupled with corruption and illegal logging has severely threatened its existence. Conservation areas have not been spared from destruction, either.
The island is the world's 5th highest island, although only the third highest in the Indonesian archipelago.
Sumatra supports a wide range of vegetation types which are home to a rich variety of species, including 17 endemic genera of plants. Unique species include: Sumatran Pine, Rafflesia arnoldii (world's largest individual flower), Titan arum (world's tallest and largest inflorescence flower).
The island is home to 201 mammal species and 580 bird species. There are 9 endemic mammal species on mainland Sumatra and 14 more endemic to the nearby Mentawai Islands. The species present include: Sumatran Tiger, Sumatran Orangutan, Sumatran Rhinoceros, Sumatran Elephant, Sumatran Striped Rabbit, Dhole, Dayak Fruit Bat, Malayan Tapir, Malayan Sun Bear and the Bornean Clouded Leopard.
The island includes more than 10 National Parks, including 3 which are listed as the Tropical Rainforest Heritage of Sumatra World Heritage Site—Gunung Leuser National Park, Kerinci Seblat National Park and Bukit Barisan Selatan National Park.
Sumatra is not very densely populated, about 96 people per km²—more than 45 million people in total. It is nonetheless the fifth most populous island in the world. The most populous regions include most of North Sumatra and central highlands in West Sumatra, while the major urban centers are Medan and Palembang.
The people composed of many different ethnic groups, speaking 52 different languages. Most of these groups, however, share many similar traditions and the different tongues are closely related. Malay-speaking people dominate the eastern coast, while people in the southern and central interior speak languages related to Malay, such as the Lampung and Minangkabau people. The highland of northern Sumatra is inhabited by the Bataks, while the northernmost coast is dominated by Acehs. Ethnic Chinese minorities are also present in urban centers.
A majority of people in Sumatra are Muslims (87%), while 10% are Christians, 2% are Buddhist and 1% Hindu. Most central Bataks are Protestant Christians—a religion introduced by Ludwig Ingwer Nommensen, a German.