, was the administrative designation for West Sumatra during its occupation and governance by the Empire of Japan from 1942 to 1945. Japanese forces entered Padang on 17 March 1942, encountering little resistance as Dutch colonial forces rapidly collapsed. Unlike most occupied territories in Indonesia, the government was headed by a Japanese civilian, rather than someone associated with the Japanese Imperial Army. Governor Yano Kenzo, the only civilian governor in occupied Indonesia, implemented policies aimed at incorporating local elites while advancing Japan's strategic and economic interests.
The early stages of the occupation initially fostered nationalist aspirations, with figures such as Sukarno and Chatib Sulaiman influencing local political developments. However, Japan's exploitative economic policies, forced labor system (rōmusha), and strict military control led to widespread suffering. Thousands of locals were conscripted into the Japanese war effort, with many forced to work on infrastructure projects such as the Muaro–Pekanbaru railway, resulting in high mortality rates. The Giyūgun (; ), the only formal military unit established in West Sumatra, later became a foundation for Indonesia's armed forces following the end of the occupation.
By 1944–1945, as the war turned against Japan, its rule in West Sumatra became increasingly repressive. Allied bombing raids, economic collapse, and growing unrest further weakened Japanese control. The occupation formally ended in stages, beginning with Japan's surrender on August 15, 1945. However, the transition to Indonesian independence in West Sumatra was marked by political maneuvers, the dissolution of Japanese institutions, and the emergence of local resistance against returning Dutch forces.
Japanese arrival
Prelude
In December 1941, the Japanese 14th Army, under the command of Vice Admiral Nobutake Kondō, successfully defeated U.S. military forces on Luzon Island, facilitating the Japanese occupation of the Philippines. Concurrently, the Imperial Japanese Navy, with intelligence from the Japanese 25th Army, sank the British battleships Prince of Wales and Repulse in Singaporean waters on December 10, 1941, which dealt a severe blow to British naval strength in Southeast Asia. With no immediate reinforcements, the British Pacific Fleet withdrew to Ceylon, leaving Malaya vulnerable to rapid Japanese advances. This loss also forced Allied forces to scatter across the Dutch East Indies, further weakening their ability to defend the region. Following these operations, the 16th Army, led by Lieutenant General Hitoshi Imamura, and the 25th Army, under the command of General Tomoyuki Yamashita, set their sights on taking control of Indonesia. From intelligence reports, the Netherlands was well aware of Japan's intention to expand its influence to Indonesia. Therefore, the Dutch tried to organize a limited militia, including cadets such as at the Military Academy in Breda into corps of vaandrigs. Sumatra itself hosted the second-largest concentration of Dutch East Indies troops, following Java. The island's defense was overseen by Major General , of the Sumatra High Command. Approximately 4,500 Royal Netherlands East Indies Army (KNIL) soldiers, including both garrison and militia forces, were stationed on the island.
The Sumatra High Command was organized into four Territorial Commands: North Sumatra, West Sumatra-Tapanuli, Riau, and South Sumatra. The Territorial Command of West Sumatra and Tapanuli, led by Lieutenant Colonel John H. M. Blogg, managed the defense of the western region of Sumatra. The Dutch stationed one infantry company each in Padang, Emmahaven (Teluk Bayur), Fort de Kock (Bukittinggi), and Sibolga. Additionally, Padangsidimpuan and Tarutung were defended by three infantry sections each. Two infantry companies, supported by a militia company, were assigned to protect Pekanbaru. Key strategic assets defended by these troops included the harbors at Emmahaven and Sibolga, as well as the airfields in Pekanbaru and Padang. To reinforce these defenses, a battery of 75mm cannon was stationed to guard Emmahaven harbor, and an airborne machine gun section was deployed to protect the Pekanbaru airfield. Beyond regular troops, the Dutch deployed a Landstorm company to safeguard critical infrastructure in western Sumatra. A (city watch) company was tasked with guarding Padang, while Bukittinggi, Sawahlunto, and Sibolga each had a section of similar units for defense. Additionally, a mobile first aid detachment operated under this command to support military efforts.
As Japanese forces advanced toward the Indonesian archipelago, Dutch officials in West Sumatra made last-minute efforts to secure local support in defending the colony. The colonial administration had long excluded Indonesians from political participation, creating deep resentment among the local population. In an attempt to shift this sentiment, Charles van der Plas, a member of the Dutch East Indies Council, visited West Sumatra. Fluent in Arabic and well-versed in Islamic teachings, he used Qur'anic verses and Hadiths to persuade local leaders that cooperation with the Dutch was in their best interest. He framed Dutch rule as a protective force against foreign invaders and urged the Minangkabau people to assist in resisting the Japanese advance. However, these appeals were met with widespread skepticism and were largely dismissed by the leaders and populace of West Sumatra, many of whom saw them as hollow attempts to maintain colonial control rather than genuine offers of inclusion. The arrival of Dutch ministers, including Finance Minister Charles Welter and Foreign Minister Eelco van Kleffens, further exposed the administration's unwillingness to enact real reforms. Arriving at Batavia in early 1942 under the Dutch government-in-exile, Van Kleffens publicly claimed that the Dutch East Indies could withstand the Japanese invasion with local support, but his assertion ignored decades of exclusionary policies that had eroded trust in the Dutch government. A failure to engage with the local population eroded trust and reinforced resentment against colonial rule. As a result, when the Japanese landed, the Dutch found themselves isolated and without the local backing they had assumed would materialize. According to a report gathered by spies operating under the F-Kikan banner, the formation of the Tripartite Pact between Japan, Germany, and Italy intensified tensions in the Pacific. In response, the Dutch government introduced a series of wartime legislative measures to mobilize the Indonesian population for defense by 10 May 1940. However, these measures inadvertently fueled widespread resentment among the local populace.
In January 1942, Japanese aircraft attacked the city of Padang. During the first attack, a plane dropped one bomb in front of Padang station, near the railroad workshops. This was the first ever bombing to occur in West Sumatra. The second attack saw seven Japanese planes over the port of Emmahaven. Contemporary Japanese records indicate that the attack on the port took place on January 27 and 28, when Japanese naval aircraft attacked freighters there. According to a Daihon'ei announcement on January 30, a 10,000-ton-class ship was sunk, while three smaller 6,000-ton-class freighters, two 4,000-ton-class vessels, and one 2,000-ton-class freighter were damaged. After circling over the city of Padang, the planes dropped bombs on ships at anchor by the docks, as well as warehouses. As a result, three large ships were sunk, parts of the warehouses and wharves were burned, and the conveyor for loading coal onto ships was damaged.
By February 1942, as part of their preparations for war, the Dutch organized various auxiliary and militia units to support the Royal Netherlands East Indies Army; these included the Stadswacht, Landwacht, and (LBD), alongside other militia preparations. The Stadswacht was responsible for localized protection in larger towns, focusing on maintaining order and guarding critical areas. Similarly, the Landwacht was established on estates and consisted of estate personnel tasked with defending their properties and, if required, assisting neighboring estates. Additionally, other auxiliary and conscript units were formed, such as the Landstorm, a militia comprising Europeans over the age of 32. Yet these preparations fell short when the Japanese arrived, because the public offered minimal support for forming such units as the Vernielingscorps (intended to carry out a scorched-earth policy), Militieplicht (a militia duty to uphold Dutch control), and the (volunteer auxiliary police). Only civil servants under duress showed minimal compliance.
Invasion
On 14 February 1942, the Japanese began their invasion of Sumatra by deploying paratroop units in Palembang. According to historian Audrey Kahin, the Japanese intended to preempt Dutch plans to damage oil installations near Palembang. The operation at Palembang involved the 38th Division of the 16th Army. The Japanese subsequently expanded their operations to other parts of Sumatra, with the 2nd Konoe Division operating under the 25th Army. By mid-March, larger numbers of troops had landed on the northern and eastern coasts of Sumatra and were moving rapidly southwards.
On 23 February, reports indicated that a Japanese motorized column of approximately 48 trucks had reached Lahat, while another column of 23 trucks and 7 tanks was advancing westward, possibly toward Bengkulu. In response, the West Sumatra and Tapanuli Territorial Commands prepared to counter the Japanese advance northward. Meanwhile, the KNIL commander in Jambi initiated the withdrawal of scattered troops from , while maintaining defensive positions at Sarolangun.
By 26 February, the Sarolangun detachment was forced to retreat following Japanese action in . While awaiting reinforcements, the detachment was tasked with delaying the Japanese advance around Muarabungo, mobilizing six squads, some drawn from the Mang detachment. Dutch forces destroyed the bridge over the , using the river's 100-meter width as a defensive barrier. However, on 28 February, Japanese forces successfully encircled the western flank of the Dutch defenses. Reinforcements dispatched from Jambi arrived too late, and the KNIL troops were ultimately repelled from Muarabungo, retreating to Muaratebo. To protect retreating forces from Central Sumatra, the KNIL command established a defensive perimeter on the west bank of the Batanghari River, setting up positions around Musang Island on 1 March.