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, and a 2010 temblor's tsunami devastated coastal areas in North and South Pagai in West Sumatra's Mentawai islands.