This is the timeline of Indonesian National Revolution.
1945 early 1945: Small, mostly Dutch, commando units parachute into northern Sumatra.
August
15 August: The Japanese surrender brings the fighting in World War II to an official close. 17 August: "Proclamation of Indonesian Independence", signed by Sukarno-Hatta. Tan Malaka, a former Indonesian Communist Party (PKI) leader, returns secretly from exile and reveals his identity in Jakarta and draws a large following. late August: A Republican government is established in Jakarta and a provisional constitution is adopted. Central Indonesian National Committee (KNIP) established. 17 to 25 August: The Japanese in Java and Sumatra disband the PETA/Giyūgun and Heiho, dismantling command structures and membership. 22 August: The Japanese announce their surrender publicly across Indonesia. August to September: Euphoria of revolution spreads across the country, while local Japanese commanders and their troops often abandon urban areas to avoid confrontation. Many discreetly allowed Indonesian youths to acquire arms. Republican youths take over infrastructure facilities in Jakarta, Yogyakarta, Surakarta, Malang and Bandung with little or no Japanese resistance. Mass pro-Republic rallies are held in Jakarta and Surabaya. Sukarno successfully convinces crowds to disperse without challenging the Japanese, thus further boosting his reputation as the only one able to prevent massive violence. Revolutionary spirit also emerges in literature and the arts.
September September: Brawls break out in Surabaya between Indonesian youths and newly freed Europeans. September: Australian forces accept the Japanese surrender in Japanese Navy area (with the exception of Bali and Lombok) bringing with them Dutch troops and administrators. early September: Following the August disbanding of the PETA/Giyūgun and Heiho, Republican armed forces begin to form from local groups of young men with charisma and/or arms. early September: Four rulers of the central Javanese principalities declare their support for the Republic. 3 to 11 September: Republican youths take over control of Jakarta railway stations, tram system and radio stations, encountering little Japanese resistance. 11 and 17 September: Mass pro-Republic rallies held in Surabaya. mid September: News of the proclamation of independence reaches all outer islands. 19 September: Pro-Republic rally of an estimated 200,000 people gathered by Tan Malaka is held in Jakarta in what is now known as Merdeka (Independence) Square. Fearing violent confrontations with the Japanese, Sukarno manages to convince the crowd to disperse. In Surabaya, the Yamato Hotel incident further fuels the flame of republicanism after a pro-Dutch gathering is countered by Republican pemuda for promoting pro-Dutch sentiments. mid-September to mid-October: Australian troops occupy the major cities of eastern Indonesia—in most cases before Republican administrations have been established—putting down demonstrations and arresting some pro-Republican officials. Pro-Republican rajas of southern Sulawesi decide against fighting the Australians and begrudgingly accept the return of the Dutch. late September: British troops, mostly Indian, reach Jakarta. late September: Major public infrastructure in Yogyakarta, Surakarta, Malang and Bandung is now controlled by Republican youths. late September: News of the proclamation of Indonesian independence has now spread to all outer islands. 9 November: First clash between Republican troops and Dutch forces in Banjarmasin.
October October: The Communist Party of Indonesia (PKI) is reconstituted after its 1920's disbanding. October: The beginnings of the so-called 'three regions affair' on the north coast of Java; it is a peasant social protest and attempts to avenge oppression under the Japanese occupation resulting in widespread violence. Actions are underway by both young Orthodox Muslim (abangan) activists and survivors of the 1926 PKI uprising against village headsmen. October: British troops, mostly Indian, arrive in Medan, Padang, Palembang, Semarang and Surabaya. To avoid confrontation, British commander Lieutenant General Sir Philip Christion, diverts soldiers of former Dutch East Indies army from Java to eastern Indonesia, where Dutch re-occupation was proceeding relatively smoothly, and there was considerable economic value. October: Tensions mount in Java and Sumatra where street fights develop between young Republicans on the one hand, and former Dutch prisoners, Dutch colonial troops (including Ambonese), Chinese, Indo-Europeans and Japanese on the other. October: The Japanese attempt to recover authority in Javan cities, which they had ceded in August and September, triggering the first stages of warfare. 3 October: Japanese Military Police (Kenpeitai) massacre Republican pemuda in Pekalongan. 3 October: After providing Indonesians ready access to arms, the pro-Republic Japanese commander in Surabaya, Vice-Admiral Shibata Yaichiro, surrenders to the first Allied representative, a Dutch navy captain. 5 October: The nucleus of the Indonesian National Armed Forces, the Public Security Armed Forces (Tentara Keamanan Rakyat), is formed on the basis of the units of the People's Security Department (Badan Keamanan Rakyat). 10 October: Japanese troops push Republicans out of Bandung and a week later hand the city over to the British. 1945, 14 October: Japanese troops begin to reclaim Semarang. Republicans retaliate by killing between 130 and 300 Japanese-held prisoners. 16 October: Sutan Sjahrir and Amir Sjarifuddin engineer a takeover within the KNIP amongst Republican deputies. On the same day Vice President Muhammad Hatta enacts Vice-Presidential Edict No.X giving it full legislative powers given concerns on the ground both of the Republican overall situation and those protesting on the attitude of Sukarno's cabinet as slow to act against the Dutch and to respond to people's needs, a Working Committee is created under the KNIP to exercise legislative duties in the event of recess of the main Committee late October to early November: Leaders of Nahdlatul Ulama and Masyumi declare that war in defence of the Indonesian fatherland is Holy War, an obligation laid upon all Muslims. The former stipulate their calls for armed war in a resolution of NU leaders. Muslims students begin to pour into Surabaya. The fiery Sutomo, (better known as 'Bung Tomo') uses the local radio to encourage an atmosphere of fanatical revolutionary enthusiasm throughout the city 20 October: Japanese have almost won Semarang but 500 Japanese and 2,000 Indonesians are killed. British troops arrive in Semarang. late October: British attempt to evacuate Eurasians and Europeans from volatile inland central Java. British detachments are sent into Ambarawa and Magelang to evacuate 10,000 detainees (mostly women and children). Air strikes are used to counter Republican resistance. 25 October: 6,000 British Indian troops arrive to evacuate Indonesian-held internees in Central Java. While initially welcomed, fights soon broke out due to Dutch contingent in relief force raising Indonesians' suspicion that British spearheading NICA who aim to recolonize Indonesia. 30 October: Sukarno and, Hatta and Amir Sjarifuddin are flown in by the British to negotiate and negotiate a ceasefire. Six hours later fighting breaks out again and British commander, Brigadier A.W.S. Mallaby is killed. In a subsequent lull in fighting, British reinforcements are brought in and the internees are evacuated.
November November: Amir Sjarifuddin followers form Pesindo (Pemuda Sosialis Indonesia, Indonesian Socialist Youth). November: So-called 'social revolutions' begin in the countryside; a competition between alternative elites and Dutch-created vs new social structures. Includes the beginnings of the so-called 'three regions affair' on the north coast of Java; a peasant social protest and attempts to avenge oppression under the Japanese occupation, which result in widespread violence. November: Sutan Sjahrir publishes a pamphlet titled Perjuangan Kita ('Our Struggle') showing him to be committed to international socialist revolution, in this he stated his criticism of murders committed upon citizens of European and Chinese ancestry (later known as the Bersiap) by patriotic pemuda and mobs inspired by Japanese propaganda during the war period. November: The Constitution is suspended in practice, although officially it remains in place. 2 November: Sukarno steps into the central Java conflict to arrange a cease fire following British requests, but fighting resumes in mid-late November and the British withdraw to the coast. 3 November: Vice-president Hatta proclaims the right of the people to form political parties. 10 November: At dawn, following Mallaby's death the previous month, British troops begin a punitive sweep through Surabaya under the cover of naval and air bombardment, but meet fanatical resistance. The city is conquered in three days, but fighting continues for three weeks. At least 6,000 Indonesians die and thousands flee. 10 November is now commemorated in Indonesia as Heroes’ Day. 11 November: Division commanders elect Sudirman as commander-in-chief of the young revolutionary armed forces, Oerip Soemohardjo was appointed chief of staff. 11 November: The cabinet is made responsible to the KNIP rather than to the president. 14 November: A new cabinet is formed; Sjahrir becomes Prime Minister and Minister for Foreign Affairs and the Interior. end November: Regents of Brebes, Tegal and Pemalang are replaced by supporters of this 'social revolution'.
December 1945, 12 November – Resident of Pekalongan is overthrown by 'social revolutionaries' and replaced with a former secret PKI member and underground leader. In retaliation, local Republican army units and 'pemuda' sweep through the three regencies arresting 1,000 supporters of the 'social revolution', which end in defeat. December: Amir's followers merge with those of Sjahrir's to form the Partai Sosialis ('Socialist Party'). December 16: Battle of Ambarawa: Republican militias and regular army servicemen defeat remnants of an Allied Anglo-Dutch expedition to take over Ambarawa and the city of Semarang from Republicans thru military means, this would be later be marked as Indonesian Army Day. mid December – Allies evacuate Japanese troops from Aceh. Civil war then breaks out between the Achenese nobility and the ulama, who are Republican. December to March 1946 – Leading uleebalangs of Aceh and their families are imprisoned or killed.
1946 January: Tan Malaka forms the Persatuan Perjuangan (Struggle Front) that aims to create unity among the organisations that exist to achieve full independence for Indonesia and reject diplomacy before the recognition of sovereignty by the Dutch. February: The Republican capital is moved to Yogyakarta following the Dutch occupation of Jakarta. February: Communist Party members clash with Republican army units. March: In east Sumatra, Bataks and Javanese plantation migrants led by leftists attack the Malay, Simalungun Batak and Karo Batak rajas. Arrest and robbery leads to slaughter and hundreds of eastern Sumatran aristocrats die, including poet Amir Hamzah. 23–24 March: In what is known as the Bandung Sea of Fire, Republicans burn Bandung's southern wards while patriotic militias flee after refusing British demands for surrender. April: Leaders of the Eastern Sumatran social revolution are arrested or go into hiding but the authority of the rajas is irrevocably weakened. April–May: 300 people are killed in Tapanuli (North Sumatra) in fighting between Toba Bataks and Karo Bataks, an ethnic conflict influenced by the Christianity among the Toba and Islam among the Karo.