North Sumatra (Indonesian: Sumatera Utara, Batak: ᯘᯮᯔᯖᯩᯒ ᯥᯖᯒ) is a province of Indonesia located in the northern part of the island of Sumatra. Its capital and largest city is Medan on the east coast of the island. It borders Aceh to the northwest, Riau to the southeast, West Sumatra to the south, the Indian Ocean to the west, and the Strait of Malacca (with a maritime border with Malaysia) to the east.
With a population of around 14.8 million in 2020 and a mid-2025 estimate of around 15.8 million (and adding about 200,000 people each year), North Sumatra is Indonesia's fourth most populous province and the most populous province outside of Java Island. At 72,437.755 square kilometres (27,968.374 mi2), North Sumatra is the third-largest province in area on the island of Sumatra behind South Sumatra and Riau. Major ethnic groups include the Malay, native to the east coast; several Batak groups, indigenous to the west coast and central highlands; the Nias people of Nias Island and its surrounding islets; and Chinese, Javanese, and Indian peoples, who first migrated to Sumatra during Dutch rule.
North Sumatra is home to the Toba supervolcano, located in what is now Lake Toba, which erupted 74,000–75,000 years ago, wiping out nearly all of humanity. The supereruption resulted in the creation of Lake Toba and was rated a VEI-8 eruption.
During Dutch rule, North Sumatra was administered under the Gouvernement van Sumatra, which governed the entire island of Sumatra out of Medan. In 1948, after Indonesian independence was proclaimed, Sumatra Province was divided into three sub-provinces, each of which had the right to regulate and manage its own affairs. The 15th of April was later designated as the anniversary of the founding of the province of North Sumatra.
History
Prehistoric era
Archaeological understanding of early North Sumatran peoples is limited compared to that of other nearby regions. Prehistoric relics in North Sumatra show that the oldest population may have been Austronesian or Melanesian. Archaeological evidence indicates that their dispersal took place in the Mesolithic era (Middle Stone Age). They spread to the eastern part of Indonesia, to the island of Papua, and to the west, to North Sumatra and the Malay Peninsula. Early peoples in North Sumatra consumed mostly snails and clams, leaving large shell deposits sometimes referred to as kjokkenmoddinger (kitchen waste), some of which are still found as hills in Saentis, Hinai, Tanjung Beringin, along the Deli-Langkat shore, and on riverbanks.
In the second wave of migration from mainland Southeast Asia c. 1000 BC, the Young Malays or Deutero Malays settled on the coast. They mainly lived by fishing and by cultivating the marshy land for agriculture. Their villages were scattered along the big rivers that flow to the east coast of North Sumatra such as Besitang, Wampu, Asahan, and Barumun. Larger villages grew at the mouths of rivers and became centres of government. Relics of the Mesolithic era have been found in North Sumatra, including finely honed stone axes, bone tools, and painting materials.
Linguistic and archaeological evidence indicates that Austronesian speakers reached Sumatra from Taiwan and the Philippines through Borneo or Java about 2,500 years ago, and the Batak probably descended from these settlers.
New genetic research has found that the Nias people also came from the Austronesian peoples, though their initial ancestors may have arrived earlier: ancestors of the Nias people are thought to have come from Taiwan through the Philippines 4,000 to 5,000 years ago. Ten years of research involving blood samples of 440 Nias people in 11 villages on Nias island show similarities between their Y-chromosome and mitochondrial DNA and that of Taiwanese and Filipino peoples.
Early historic era
The eastern coast of North Sumatra, bordering the Strait of Malacca, has been widely visited by Hindus and by Chinese traders for centuries since the founding of early Situs Kota Cina or Chinatown sites in Hamparan Perak c. 11th–14th centuries AD. Barus, a trading port on the western coast of Tapanuli, attracted Middle Age era traders in search of camphor, which was popular in Ancient Egypt. In 1030, Rajendra Chola recorded the names of North Sumatran states he defeated in one expedition to conquer Srivijaya. States that he mentioned included Sriwijaya, Malayur, Kendara, and the Panai Kingdom. Furthermore, the Nagarakretagama epic by Mpu Prapanca from the 14th century lists states found in North Sumatra such as Pane, Haru, Mandailing, Tamiang, Lawas, and Barus, which were mainly defeated by the Majapahit.
The earliest kingdom that was present on the eastern coast of North Sumatra was the Aru Kingdom, which existed from the 13th to the 16th century AD. In its height, the kingdom was a maritime power and controlled the northern part of the Malacca strait. The kingdom was initially established as a Karo polity. The indigenous population practiced native animism and Hinduism. Starting in the 13th century, some also practised Islam. Aru's capital was located close to present-day Medan and Deli Serdang. Its people are believed to have been descendants of the Karo people from the hinterland of North Sumatra.
An area near Lake Toba called Batakland (or the Batak Lands) housed kingdoms of Batak people. It was first mentioned in Zhao Rugua's 13th-century Description of the Barbarous Peoples, which refers to a 'Ba-ta' dependency of Srivijaya. The Suma Oriental, written in the 15th century, also refers to the "Kingdom of Bata" between Pasai and the Aru kingdom. The Batak mainly practiced animism and cannibalism and remained isolated from foreign culture and kingdoms like Srivijaya and Majapahit. The Toba people divided the Batak Lands into several independent kingdoms, which often entered into defensive alliances. Of the many kingdoms, Bakkara and their king or Sisingamangaraja held the most leverage due to customs and traditions which consider Bakkara the place of origin of the Batak people.
The Nias people on Nias Island remained isolated during its early era. Its people practised agriculture and cultivation, made art carvings, and adhered to shamanist and pagan practices.
Kingdom, sultanate, and colonial era
By c. 1500, there were several kingdoms on the east coast of Sumatra, namely the larger Nagur and Aru kingdoms and the smaller Panai and Batangiou kingdoms. To the west, in the hinterland of Tapanuli, another kingdom emerged: a Batak kingdom founded by descendants of Sisingamangaraja. This kingdom gradually expanded its influence throughout Tapanuli to Angkola, Mandailing, and Dairi. The three largest kingdoms in North Sumatra in the sixteenth century were Nagur, the Batak kingdom under the rule of King Sisingamangaraja, and Aru.
Wars between these three kingdoms made the region vulnerable to outside influences from Aceh, Melaka, the Portuguese, Siak, and Minangkabau. The Sultanate of Aceh worked to spread Islam across the eastern coast, and in the Padri War, succeeded in spreading Islam into the southern Tapanuli kingdom. As a result of this warfare and cultural shifts, the three big kingdoms split into several small kingdoms and sultanates, including Deli, Serdang, Asahan, Langkat Sultanate, Maropat and Lingga.
Malacca fell to the Dutch East India Company (the VOC) in 1641. Coastal areas of North Sumatra felt economic impacts as the VOC subsequently reduced the presence of trade in Malacca and shifted resources towards Batavia. Nevertheless, North Sumatra also saw an increase in Arab, Chinese and Indian traders.
After Britain gained a position on the nearby island of Penang by establishing a trading post for the British East India Company (Britain's first such post in the Far East) in 1786, the British traded heavily with the east coast of Sumatra. Prior to the nineteenth century, Dutch power was concentrated on the island of Java and parts of the Moluccas, the Dutch East India Company competed with the British East India Company for trade in the area, especially for pepper, with the two nations trying to obstruct the other's trade efforts. In the nineteenth century, the Dutch began to focus more on areas outside Java, including North Sumatra, driving out British influence. Dutch control was formalized with the handover of most of Indonesia in the 1814 Treaty of London, which was renewed in the 1824 Treaty of London. However, the UK maintained a presence in several places that were considered important for trade, including parts of Sumatra and Kalimantan.
During the Padri War, in the years prior to 1860, Dutch forces arrived in South Tapanuki at the request of a local leader to provide protection. The Siak sultan subsequently signed a treaty with the Dutch East Indies government recognizing Dutch authority over it and the sultanates of Asahan, Serdang, Deli and Langkat. The Dutch proceeded further into Batakland and North Sumatra, invading Toba, Karo Highland, Nias and Silindung with the help of Christian missionaries, such as Ludwig Ingwer Nommensen, who worked to evangelise the area. The Dutch invasion into Batakland met resistance by Sisingamangaraja XII, causing a guerilla war lasting 30 years until and Sisingmangaraja XII's death in battle and a subsequent Dutch victory. Meanwhile, particularly after 1869, Dutch tobacco plantation activities expanded on the east coast, including the establishment of Deli Maatschappij and London Sumatra, using land leased from the Malay sultans. As there was a worker shortage, the Dutch began importing labourers from Java, Southern China and Southern India. This first big wave of migration established substantial Javanese, Chinese, and Indian populations in North Sumatra that remain to this day. By 1874, the sultanates had been formally included within the Dutch East Indies, and in Deli, the sultan of Deli granted the Dutch sole rights over taxation and leases, in exchange for an annual pension. That year, the East Coast Residency was established.
On March 12, 1942, Japanese forces landed in Palubuhan Ruku on the east coast, and advanced on Medan. The advance force reported it had captured the town the next day. The main force followed on bicycles. There was some resistance from the Dutch forces, particularly around Pematangsiantar, but the last major town, Sibolga, fell on 15 March. During the Japanese occupation of North Sumatra, the leader of the Japanese Armed Forces was centred in Bukittinggi, moving the de facto capital out of the Dutch centre of Medan. The occupation lasted 3 years. In 1945 the Japanese occupation officially ended with Japan's surrender in the Pacific and two days later Sukarno declared Indonesian Independence, beginning the four-year Indonesian War of Independence against the Dutch.
Independence and contemporary era
Beginning on 3 March 1946, there was a social revolution in East Sumatra. Across 25 "native states", many sultanates were overthrown. Armed pergerakan groups (Indonesian nationalists) conducted mass killings of the members of aristocratic families. To opportunistic pergerakan militants (including Communist Party of Indonesia members Xarim MS and Luat Siregar), the revolutionary movement was seen as a means for East Sumatra to be freed from colonial rule and to join the larger Indonesian National Revolution. Participants of the revolution were believed to be provoked by leaders to kill aristocrats and create violence with three prime objectives: to eliminate the sultans and aristocrats (who were seen as Dutch allies), to seize their wealth (to fund the Indonesian independence campaign), and to eliminate the region's feudal social structure.
The Dutch authorities, working with the East Sumatra Union (Persatuan Sumatra Timur), which had been formed in 1938 by westernized Malay elites to reassert Malay and Simalungun ethnic interests, established the State of East Sumatra (Indonesian: Negara Sumatra Timur (NST)) as part of the planned United States of Indonesia. The state lasted from December 1947 to August 1950. In addition to the Dutch, the NST state was supported by Malay aristocrats, most of the Simalungun rajas, some Karo chieftains, and Chinese groups who felt that the revolution threatened their interests. Dr Tengku Mansu, a member of the Asahan royal family, was selected as head of state for the NST. While the Dutch wanted the NST to be seen as an orderly and progressive alternative to the republic, western-educated aristocrats saw it as a bastion for their own ethnic interests. Following the Dutch-Indonesian Round Table Conference in late 1949, the Dutch withdrew military support for the State of East Sumatra and its local authority began to collapse. The short-lived state was viewed with suspicion, and Dr Tengku Mansur entered into negotiations with Mohammad Hatta to reunify East Sumatra with the Republic of Indonesia in May 1950. Mansur surrendered authority to the republic and East Sumatra merged with Tapanuli to become the province of North Sumatra on August 15, 1950.
After Indonesian independence, at the first session of the National Committee of Regions (KND), Sumatra was divided into three sub-provinces: North Sumatra, Central Sumatra and South Sumatra. North Sumatra was an amalgamation of three administrative regions called Residencies: the Residency of Aceh, the East Sumatra Residency, and the Residency of Tapanuli. The publication of the Law of the Republic of Indonesia (R.I.) No. 10, Year 1948 on April 15, 1948, formalized the division of these three provinces. The date of 15 April 1948 has been subsequently celebrated as the anniversary of North Sumatra Province.
Act R.I. No. 24 of 1956, promulgated on 7 December 1956, established a separate Aceh Province, independent of the province of North Sumatra.
Geography
The province of North Sumatra stretches across the island of Sumatra, between the Indian Ocean and the Strait of Malacca, with an area of 72,437.755 km2. It borders the province of Aceh to the northwest and Riau and West Sumatra to the southeast. The province contains a broad, low plain along the Strait of Malacca on which the provincial capital, Medan, is located. In the south and west, the land rises to the Bukit Barisan mountain range that runs the length of Sumatra; the mountains here surround Lake Toba, which was formed from the caldera of an ancient volcano. Several large islands in the Indian Ocean off the west coast of Sumatra are currently part of North Sumatra, most notably Nias Island and the Batu Islands.
There are 419 islands in North Sumatra. The outer islands include the island of Simuk (the most westerly of the Batu Islands) and the island of Berhala in the Strait of Malacca. The Nias archipelago, located off the coast of western Sumatra in the Indian Ocean, consists of Nias Island and other much smaller islands in its vicinity. Its administrative centre is located at the city of Gunungsitoli on the northeast coast of Nias. The Batu Islands, just southeast of Nias, consist of 51 islands including three major islands: Pini, Tanahbala and Tanahmasa. Pulau Telo is their administrative centre on the small island of Situasi. Other islands in North Sumatra include Imanna, Pasu, Bawa, Hamutaia, Batu Makelele, Masa, Bau, Simaleh, Makole, Jake, and Wunga.
Half of the province is located on a high plateau that runs along the Bukit Barisan mountains, from central North Sumatra to the western coast. The tallest mountain in the province is Mount Sinabung in Karo Regency, at elevation around 2,460 metres (8,070 ft), the most active volcano in the region. Volcanic activities (cracks where steam, gas, and lava are emitted) were observed at the summit in 1912; recent documented events include an eruption in the early hours of 29 August 2010 and eruptions in September and November 2013, January, February and October 2014. Another volcano nearby is Mount Sibayak, also located in the Karo highland, sitting at an elevation of 2,181 metres (7,156 ft). Crystalline sulfur deposits on Mount Sibayak have historically been mined on a small scale, and seepage of sulfurous gases has caused acidic discolouration of its small crater lake.
Lake Toba is the site of a supervolcanic eruption that occurred 69,000 to 77,000 years ago, estimated at VEI 8, that formed a climate-changing event. Recent advances in dating methods suggest more precise dating at 74,000 years ago. It is the largest-known explosive eruption on Earth in the last 25 million years. It has been accepted that the eruption of the Toba Caldera led to a volcanic winter with a worldwide decrease in temperatures between 3 and 5 °C (5.4 and 9.0 °F), and up to 15 °C (27 °F) in higher latitudes. Additional studies in Lake Malawi in East Africa show significant amounts of ash deposited by the Toba Caldera eruptions, despite a great distance from the area, but these studies offer little indication of a significant climatic effect in East Africa. According to the Toba catastrophe theory, the eruption killed most humans living at that time and is believed to have created a population bottleneck in central East Africa and India, affecting the human genome to the present day. More recent studies have cast doubt on this theory and found no evidence of substantial changes in population.
In North Sumatra, there are currently two national parks: the Gunung Leuser National Park and Batang Gadis National Park. According to the Ministerial Decree No. 44 of 2005, forest area in North Sumatra today covers 3,742,120 hectares (9,247,000 acres), consisting of a 477,070-hectare (ha) Natural Reserve Area/Natural Conservation Area, 1,297,330 ha of protected forest, 879,270 ha of limited production forest, 1,035,690 ha of permanent production forest, and 52,7600 ha of production forest that can be converted to another status.
However, the above figure is only de jure. In reality, the forests are not as large as the figures suggest. A lot of the forests are damaged, due to encroachment and illegal logging. So far, over 206,000 ha of forests in Sumatra have experienced changes in function. As many as 163,000 ha were converted to plantations and 42,900 ha were transmigration areas.
Governance
The administrative centre of North Sumatra is located in the city of Medan, governed by a governor. Earlier governments ruled all of Sumatra (1945–1950); and a North Sumatra Province that included Aceh (1950–1956). In 1956, Aceh split off to form a separate Aceh Province.
Administrative divisions
North Sumatra is currently subdivided into 25 regencies (kabupaten) and 8 autonomous cities (formerly municipalities). When originally created as a province with its current boundaries, it was composed of 10 regencies and 6 cities, but an 11th regency (Dairi Regency) was created on 23 September 1964. Fourteen more new regencies and two new cities were created between 1998 and 2008. All these are listed below with their areas and their populations at the 2010 census and the 2020 census, together with their official estimates for mid-2025. Regencies and cities are sub-divided into 455 districts, which in turn are further sub-divided into 6,110 villages (as of early 2024). Proposals have been under consideration since 2013 by the People's Representative Council (Dewan Perwakilan Rakyat or DPR) to create three new provinces from parts of the present North Sumatra: Nias Islands, Tapanuli, and East Sumatra; however since 2013 the Indonesian Government have maintained a moratorium on the intended creation of new provinces, regencies and cities. The present regencies and cities are grouped for convenience below according to the projected new provinces within which they are situated:
Nias Islands Region
This region contains the substantial island of Nias and various small offshore islands, including the Batu Islands to the south. Originally it comprised a single Nias Regency (created on 7 November 1956), but on 25 February 2003 the southern part of the island (including the Batu Islands) was split off to form a separate South Nias Regency. On 29 October 2008 two new regencies - North Nias and West Nias - together with the city of Gunungsitoli, were split off from the remainder of Nias Regency.
Notes: (a) UU is an abbreviation from Undang-Undang (the Indonesia statute of law). (b) South Nias Regency includes the Batu Islands.
The region include 124 smaller offshore islands - 87 in South Nias Regency (primarily the Batu Islands), 11 in West Nias Regency, 19 in North Nias Regency and 7 in Nias Regency.
Tapanuli Region
This region comprises the southwestern part of the province on the island of Sumatra, and equates to the former Tapanoeli Residency which existed at the time of independence (except for Nias Island). When the province was created, the region comprised three regencies (North Tapanuli, Central Tapanuli and South Tapanuli) and the city of Sibolga. A fourth regency - Dairi - was created on 23 September 1964 from part of North Tapanuli Regency. Two more new regencies were formed on 23 November 1998 - Mandailing Natal from part of South Tapanuli Regency, and Toba Samosir from another part of North Tapanuli Regency. The city of Padang Sidempuan was split off from South Tapanuli Regency on 21 June 2001. Two further regencies were formed on 25 February 2003 - Humbang Hasundutan from part of North Tapanuli Regency, and Pakpak Bharat from part of Dairi Regency. A new Samosir Regency was created from part of Toba Samosir Regency on 18 December 2003 (more recently, the remaining part of this regency was renamed Toba Regency). Another two regencies were created on 17 July 2007 - Padang Lawas and North Padang Lawas, both from parts of South Tapanuli Regency.
The region includes 60 small offshore islands - 24 in Mandailing Natal, 31 in Central Tapanuli (the largest being Mursala Island off Sibolga) and 5 in Sibolga City, plus 7 islands in the landlocked Lake Toba comprising 1 in North Tapanuli Regency (Pulau Sibandang), 5 in Samosir Regency and 1 in Humbang Hasundutan Regency.
East Sumatra Region
The region comprises the northeastern part of the province on the island of Sumatra, and equates to the former State of East Sumatra which existed at the time of independence. It now covers ten regencies and five cities, but originally there were just six regencies and the five cities. The new regency of Serdang Bedagai was formed on 18 December 2003 from part of Deli Serdang Regency, and the new regency of Batubara was formed on 2 January 2007 from part of Asahan Regency. Two further regencies were formed on 24 June 2008 - North Labuhanbatu and South Labuhanbatu - both from parts of Labuhanbatu Regency.
The region includes 38 offshore islands - 11 in Langkat Regency, 1 in Deli Serdang, 1 in Medan City, 2 in Serdang Bedagai, 1 in Simalungun, 2 in Batubara, 4 in Asahan, 8 (riverine islands) in Tanjungbalai City, 2 in North Labuhanbatu and 6 in Labuhanbatu Regency.
National Electoral Districts
The province comprises three of Indonesia's 84 national electoral districts to elect members to the People's Representative Council. Each of the three districts elects 10 members to the People's Representative Council (for a total of 30 members from the province).
The North Sumatra I Electoral District consists of 2 of the regencies in the province (Deli Serdang and Serdang Bedagai), together with the cities of Medan and Tebingtinggi.
The North Sumatra II Electoral District consists of 16 regencies (Nias, South Nias, North Nias and West Nias; Samosir, Toba, North Tapanuli, Humbang Hasundutan, Central Tapanuli, South Tapanuli, North Padang Lawas, Padang Lawas and Mandailing Natal; Labuhan Batu, South Labuhan Batu and North Labuhan Batu), together with the cities of Sibolga, Padangsidempuan and Gunungsitoli.
The North Sumatra III Electoral District consists of the remaining 7 regencies (Asahan, Simalungun, Dairi, Karo, Langkat, Pakpak Bharat and Batubara), along with the cities of Tanjungbalai, Pematangsiantar and Binjai.
Demographics
Population
North Sumatra recorded a population of 12,985,075 in the 2010 national census, making it the 4th most populous province in Indonesia, with a sex ratio of 99.59 men per 100 women. The 2015 Intermediate census gave a total of 13,923,262, while the 2020 census gave a total of 14,799,361, and the official estimate for mid-2025 was 15,785,839 The mid-2025 total comprised 7,922,846 males and 7,862,993 females, giving a sex ratio of 100.76 men per 100 women.
Migration
It was reported in January 2024 that a group of 140 Rohingya people, consisting mostly of women and children had landed in Indonesia and been directed by the military to the North Sumatra region. This has been one of several groups that have arrived in the area over the preceding months.
Ethnic groups
North Sumatra is a multi-ethnic province. The Malay people are regarded as the majority people of the east coast of the province, while the west coast of the province is mainly inhabited by the Batak (Pakpak, Angkola and Mandailing groups). The central region around Lake Toba to the northern Karo highland is predominantly inhabited by other Batak groups (Toba, Simalungun and Karo). The Nias people are indigenous to Nias Island and its surrounding islets. With the opening of tobacco plantations in East Sumatra during the colonial era, the colonial government employed many contract labourers for plantations, they were mainly Chinese, Javanese and Indian migrants, who were majority does not returned after end contract and decided to stay in North Sumatra. The rapid urbanisation in the province also attract neighbouring people from Aceh, Riau and West Sumatra, which is the Aceh and Minangkabau people presents.