The East Sumatra revolution, also known as the East Sumatra social revolution (), began on 3 March 1946. Across 25 "native states", many sultanates were overthrown and mass killing of members of the aristocratic families were performed by armed pergerakan groups (Indonesian nationalists). To the opportunistic pergerakan militants (especially Communist Party of Indonesia leaders Abdoe'lxarim M. S. and Luat Siregar), the revolutionary movement was seen as one of the means for East Sumatra to be freed from colonial overlordship 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. These belligerents had three prime objectives: to eliminate the sultans and aristocrats (who were seen as Dutch allies), to seize their wealth (as sources of funding for the Indonesian independence campaign) and to eliminate the region's feudal social structure. The revolution brought about the formation of the State of East Sumatra, which was dissolved when the region became part of the Indonesian republic.
Background The Dutch subjugated the Minangkabau of Sumatra in the Padri War and the Dutch expedition on the west coast of Sumatra occurred. There followed the conquest of the Aceh Sultanate of Sumatra.
East Sumatra during colonial period was dominated by plantation with workers from diverse ethnicities. This was exploited by capitalism of European and benefit for local aristocratic group such as local chiefs and sultans. As government power became unstable because of Japanese occupation, tension between ethnicities and social class erupted.
East Sumatra under the Dutch (1930s–1942)
Ethnic tensions
The influx of Chinese, Javanese, and other ethnic immigrants to the region during the 1930s gave rise to several official associations associated with the kingdom to identify certain customary elements to form the cultural core of the East Sumatra society. Even though the Karo, Malays, and Simalungun peoples were all recognised as indigenous communities in the region, the royalty and associations chose to emphasize more on preserving the Malay cultural identity. Special privileges were granted to the Malays (such as accessing to plantation land) by the Dutch and the social status of the Malays appeared to be much higher than the other indigenous communities in East Sumatra. As a result, members of the other two indigenous communities as well as the other locals felt this was unfair and that resulted in unwanted ethnic tensions. An increasing number of locals began to disagree with the Dutch and the Malay aristocrats due to the bias that these elites had towards the Malays.
Religious divisions and Islamic movements Another division between the Malays and the two groups was religion, whereby the Malays were mostly Muslims and majority of the Karo and Simalungun were Christians or animists. Despite being the third-largest group in the 1930s, the Javanese, in particular the Abangan, were perceived by the Malays to have a lower social status and their practice of Islam was seen to be nominal. The Malays were usually regarded as the traditional protectors of Islam by the authorities and the other Muslim reformist forces who advocated an Islam different from the Malay orientation were seen as threats to the authority of the sultans. The former was known as the Kaum Tua (old group) and the latter as the Kaum Muda (young group, reformist) who "...sought to free the Islamic communities from superstitious beliefs.".
There were two major modernist Islamic movements launched by the Kaum Muda: firstly, the Muhammadiyah movement that involved conflicts over religious texts and teachings and secondly, the Jamiatul Wasliyah organization which shared common interests with Muhammadiah. Even though the Kuam Muda presented themselves as "non-political" Islamic leaders, the kerajaan, literally means 'kingdom,' which in this case refers to the indirectly ruled states of Dutch East Indies, still regarded those organizations with hostility and decided to support the Kuam Tua instead. Hence, the Malays were said to claim dominance in both political and cultural spheres, which led to resentment of the Malay aristocratic class and Malays in general.
The political movement During the late 1930s, the national movements led by the pergerakan were developing rapidly among urban and educated sections of the Indonesian community. One example was the East Sumatra Association, which was created in 1938 by Dutch-educated Malays and was later led by Dr Tengku Mansur (who was connected to the Asahan royal family). The political association aimed to improve the social status of East Sumatran natives, including Simalungun people and Karo people (Indonesia). The national movement then slowly reached out to small farmers of the tobacco-growing area, which eventually provided the rudiments of an important rural base for the two nationalist parties, GERINDO and PARINDRA in East Sumatra. Besides raising voices that disagreed with the Dutch repression and Malay aristocracy, the two parties also played important roles in initiating and mobilizing resources to support the 1946 East Sumatra social revolution.
East Sumatra during the Japanese occupation (1942–early 1945)
During the occupation, the Japanese implemented policies that were perceived as a continuance of Dutch support for the kerajaan. Under the policies, the kerajaan were able to gain access to various incomes, titles, and religious authority that they used to have in the 1930s. However, Japanese used available fragmentation between the pergerakan and the kerajaan. The regaining of Malay aristocrats' power during the Japanese Occupation resulted in suppression of the peasant community in East Sumatra. Many Japanese officials managed to exploit food and labour supplies from the peasantry through the kerajaan hierarchy and that had increased the amount of economic pressure faced by the farming population of East Sumatra. Although, moderate members of PARINDRA, one of the pergerakan nationalist parties, even took the initiative to form a Comité Indonesia in an attempt to present a united pergerakan front to the Japanese. They were motivated to launch a new Indonesian-controlled administration with the support from the Japanese. However, the garnering of support from the Japanese did not work out well because the priority of the Japanese was to obtain the oil and plantation produce from East Sumatra rather than making any significant political changes to the existing government structures. Furthermore, the policies adopted by the Japanese were seen as a continuance of Dutch support for the kerajaan that caused nationalists to hold stronger negative feelings towards the Sultans and Malay aristocrats.
Consequently, the credibility of those traditional, nationalists and religious leaders, who were assigned by the Japanese, was severely damaged. A new leadership was then formed by a group of pemuda (youth) who had received their formative education under the Japanese military groups (Giyūgun, Heiho and Tokkeitai). The military training guided by Japanese ethics and values fanned their nationalism and motivated them to defend their lands. These Japanese-trained pemuda then took on active roles in fighting against the Dutch and Malay sultans during the 1946 East Sumatra Social Revolution.
Allied landings, local struggles and period of uncertainty (late 1945–1946) After the Japanese surrendered, the independence of Indonesia was declared in Jakarta and Sukarno was chosen as the president of a new republic. Sumatra was then declared to be a province of the new republic and Medan was chosen as its capital. Despite this, many leaders were worried about the possibility of the Dutch returning and of the Malay and Batak aristocrats regaining their former power.
From 21 August, leaflets were sent to Sumatra on Netherlands Indies Civil Administration. Japanese surrender was publicly announced on 22 August. On 25 August, Naval Lt. Brondgeest and Dutch-dominated unit landed near Pangkalan Brandan. Brondgeest, by 1 September, had been established base in Medan and contact with Japanese, Sultan of Deli, Sultan of Langkat, and other cooperative natives. This cooperative native asked for some reforms. Brondgeest decided to act independently from British and Japanese with local Ambonese and Menadonese as police force to control Medan and Republican movement. The Muslim fast was ended on 7 August and celebrated by mending relation with pro-Dutch peoples. On 14 September, Lt. Westerling and 3 others who were part of Dutch commando entered Medan to equip the police force.
Many of the Japanese-trained unemployed pemuda of ex-Giyugun were then recruited by Abdoe'lxarim M. S. – the executor of the former Badan Oentoek Membantor Pertahanan Asia (Body for Assisting the Defence of Asia / BOMPA) property, who fed them BOMPA rice-stocks, and were then organised into a broader Persatuan Pemuda Latihan (Trained Youth Association) which include police, soldiers, and officials. On 23 September, the senior ex-Giyugun officer, First Lieutenant Achmad Tahir issued a meeting for all Japanese-trained Pemuda in Asrama Rensheikei. Among these groups, some had contact with 'underground' groups with pre-war left wing experience. These groups include Karo group under the leaderships of Selamat Ginting, Tama Ginting, and Rakutta Sembiring Brahmana, and an "anti-fascist" group under Nathar Zainuddin a veteran Islamist communist, which include Urbanus Pardede, Bustami, Joenoes Nasution, and Marzuki Lubis. They plan to contact with Aminuddin Nazir of Inoue's coastal guard and by evening Badan Pemuda Indonesia or BPI was formed under Achmad Tahir as First Chairman. Before the landings of the Allied (British) forces, these young pemuda were actively propagating information about the republic. They persuaded the senior Indonesian officials to resist the Japanese, the Dutch and Malay aristocrats. Therefore, these pemuda were seen as very nationalistic, eager to resist the return of the Dutch, and unsympathetic to the various kerajaan." On 6 October, new Sultan of Deli who was known for his skeptic of Republic was installed. By 10 October 1945, Tentara Keamanan Rakyat or TKR of East Sumatra was formed with Achmad Tahir as Commander, Soetjipto as Chief-of-Staff, Capt. Hotman Sitoempul in Siantar, Lt. Martinus Lubis in Brastagi, and Lt. Djamin Ginting in Kabanjahe.