North Kalimantan

North Kalimantan is a province of Indonesia, occupying the northernmost section of Kalimantan, the Indonesian part of Borneo. It shares borders with the Malaysian states of Sabah to the north and Sarawak to the west, and with the Indonesian province of East Kalimantan to the south. The capital is the town of Tanjung Selor, while Tarakan serves as the province’s only city, its largest urban center, and its financial hub. The province was created on 25 October 2012, when it was split from East Kalimantan with the goals of narrowing development gaps and countering Malaysian influence in the area. Covering 69,901 square kilometres, North Kalimantan comprises four regencies and one city. Its population stood at 524,656 in the 2010 Census and rose to 701,784 by the 2020 Census, making it Indonesia’s least populous province at that time—a status it held until the 2022 creation of South Papua, West Papua, and Southwest Papua. The mid-2025 official estimate placed the population at 749,370, with 393,130 males and 356,240 females. Much of the province remains sparsely inhabited.

Historically, the region was the domain of the Sultanate of Bulungan, founded by a group of coastal Kayan. Around the 16th century, a Kayan princess named Asung Luwan married a visiting Brunei nobleman, Datuk Mencang. Their lineage established a princely state centered in Tanjung Selor, ruling over what are now Bulungan, Tana Tidung, Malinau, Nunukan, Tarakan, and parts of Sabah. Bulungan was a vassal of the Berau Sultanate, which in turn answered to the Kingdom of Kutai. After later conflicts, the territory fell under Brunei’s control and, following agreements with the Sultanate of Sulu, officially came under Sulu’s authority. In 1777, the royal family converted to Islam; King Wira Amir changed his name to Aji Muhammad and took the title Sultan Amirul Mukminin. In 1853, the Dutch imposed a Politiek Contract that asserted sovereignty over the Bulungan kingdom—Sulu, then at war with Spain, could not respond. In 1881, the British North Borneo Company was formed, placing North Borneo (modern Sabah) under British rule and claiming the Tawau region. Under Dutch control, the sultan was forced to cede the Bahau River, Pujungan River, and Apo Kayan areas. After lengthy negotiations with the British, the Dutch recognized the British borders in 1915, which became the modern boundary between Sabah and North Kalimantan. During World War II, Japanese occupiers struck an agreement with Bulungan to share natural resources, and in exchange the region largely avoided the Romusha forced-labor system.

During the Indonesia–Malaysia confrontation in 1963, the Sultanate of Bulungan took an ambiguous stance on Malaysia’s formation. In April 1964, a document was reportedly found linking the Bulungan aristocracy to Malaysia, suggesting they would support Malaysia’s formation and potentially join it. On 24 April 1964, Brigadier General Soeharjo, leader of the Mulawarman regional military command, ordered the capture and killing of Bulungan aristocrats. On 2 July 1964, Lt. B. Simatupang and Captain Buntaran were received cordially by the Sultan. The next day, units of Brawijaya 517 invaded the palace, burning and looting it and killing members of the royal family. According to Burhan Djabier’s 1991 book *East Kalimantan: The Decline of a Commercial Aristocracy*, the central TNI leadership did not act against Soeharjo because he was a known leftist with political connections. Most leftists and the PKI were hostile to royals, drawing parallels to the East Sumatra revolution. The sultanate’s position, as stated by Dato’ Seri Pangeran Sanusi Hussin, holds that the PKI was responsible for the palace burning and ethnic cleansing. Surviving royal family members fled and became Malaysian citizens. In 2017, they announced they were in the process of regaining Indonesian citizenship.

Transportation in the province is served by Tarakan Airport, also called Juwata International Airport, on the island of the same name, along with an international ferry port connecting to Tawau in Malaysia. There are no international land crossings; entering the mainland requires a ferry from Tarakan or road access from the south. Large sections of the province’s roads remain unpaved muddy ditches. The airport’s runway and apron are shared with Suharnoko Harbani Air Force Base, a Type A base of the Indonesian Air Force. Named after a former Minister of Industry and Air Force officer, the base was established in 2006 as part of national defense strategy, particularly in response to tensions with Malaysia over Ambalat. Before the base’s formation, an Air Force post existed under the Balikpapan Air Force Base. Because the airport serves both military and civilian aviation, the apron is shared. In July 2014, airport authorities began building a 183-meter taxiway to the military apron, designed to accommodate four Sukhoi and two Hercules aircraft simultaneously; the project was expected to finish in December 2014. The Trans-Kalimantan Highway was completed in early 2019 under President Joko Widodo’s administration.