# Battle of Ambarawa

The Semarang offensive is composite of the Battle of Ambarawa (20 October–15 December 1945; 55 days), Magelang offensive (26 October–15 December 1945; 49 days), Battle of Ungaran or Ungaran offensive, and Semarang offensive proper (Indonesian: Palagan Ambarawa). This major battle took place between the recently created Indonesian Army and the British Army with the Dutch forces that occurred between 20 October 1945 and 2 March 1946 in Semarang city, Semarang Regency, and Magelang Regency in Central Java, Indonesia. Perhaps the most successful Indonesian offensive of the Indonesian Revolution, this offensive tightened British and Dutch control from the Magelang and Semarang metropolitan areas to only Semarang city. In modern times, 15 December is celebrated as the Indonesian National Infantry Day.

## Prelude

On 19 October 1945, Allied troops under the command of Lieutenant-Colonel Edwardes landed in Semarang to disarm Japanese troops and liberate POWs still detained in camps in Central Java. Initially, the troops were welcomed by the Indonesians because their presence halted the attacks on them by Japanese troops in revenge for the massacre of around 200 imprisoned Japanese civilians by Indonesian "extremists" in nearby Semarang. The troops were under orders to remain neutral in "political matters". At a meeting with Central Java governor Wongsonegoro, agreement was reached that the Indonesian police would be allowed to keep their weapons, but that civilians would be disarmed. In return agreed to provide foodstuffs and other necessities for the smooth running of the Allied task, while the Allies promised not to interfere with the sovereignty of the current government.
However, when Allied and NICA troops began freeing and arming freed Dutch POWs in Ambarawa and Magelang, many locals were angered. Relations were further ruined when the Allies began disarming members of the Indonesian Army. 1st Central Kedu Regiment under the command of Lieutenant Colonel M. Sarbini began besieging Allied troops stationed in Magelang in reprisal for their attempted disarmament. Indonesian president Sukarno intervened in the situation to calm tensions, and the Allies secretly left Magelang to their stronghold in Ambarawa. Sarbini's regiment followed the Allies in pursuit, and was later joined by other Indonesian troops from Ambarawa, Suruh, and Surakarta. The retreat of the Allied troops was halted at Jambu Village because it was blocked by the Young Force troops under the leadership of Oni Sastrodihardjo. Allied troops were later driven out of the nearby village of Jambu by the combined force of the Indonesian Army.
At the village of Ngipik, Allied troops were again intercepted by Soerjosoempeno's 1st Battalion at Ngipikand were forced to retreat again by the Indonesian Army, after attempting to establish control over two villages around Ambarawa. Indonesian troops under the command of Lieutenant Colonel Isdiman tried to free the two villages, but Isdiman was killed in action before reinforcements arrived. Since the death of Lt. Col. Isdiman, the Commander of the 5th Banyumas Division, Col. Soedirman felt the loss of one of his best officers and he immediately took to the field to lead the battle. Colonel Soedirman, vowed to avenge Isdiman's death and called in reinforcements to besiege Allied positions in Central Java. Unknown to his servicemen, he had been elected Commander of the Armed Forces on 12 November in absentia, as he was still with his division.

## Battle

On the morning of 23 November 1945, Indonesian troops began firing on Allied troops stationed in Ambarawa. A counterattack by the Allies forced the Indonesian Army to retreat to the village of Bedono.
On 11 December 1945, Soedirman held a meeting with various commanders of the Indonesian Army. The next day at 4:30 AM, the Indonesian Army launched an assault on the Allies in Ambarawa. Indonesian artillery pounded Allied positions, which were later overrun by infantry. When the Semarang-Ambarawa highway was captured by Indonesian troops, Soedirman immediately ordered his forces to cut off the supply routes of the remaining Allied troops by using a pincer maneuver. Col Soedirman's presence breathed new life into the Indonesian troops. Coordination was held between sector commands and the siege against the enemy tightened. The tactic applied was an impromptu attack simultaneously in all sectors. Reinforcements continued to pour in from Yogyakarta, Surakarta, Salatiga, Purwokerto, Magelang, Semarang, etc. The battle ended four days later on 15 December 1945, when Indonesia succeeded in regaining control over Ambarawa and the Allies retreated to Semarang.

### Battle of Magelang

On October 1945 the British-Dutch combine forces marched through Magelang,after they arrived in Magelang the British forces caused the chaos in Magelang by kidnapping the Indonesian youth forces and tortured them however the Indonesian forces responding this action by launched major assaults on Magelang. In this assault the Indonesian forces managed to ambushed and attacking the British-Gurka and Dutch forces, to countered this assault the British called some air support,in the aerial attack the British aircraft bombed the village in Magelang and killed tenth Indonesian soldier and hundreds of civilians. However the Indonesian forces able to stopped the British-Dutch convoy and forced them to retreated.

### Battle of Ungaran

On 1945 the Indonesian forces led by Major Soeyoto launched an ambush to an allied convoy in Ungaran,Semarang Regency. The convoy was backed by one P-51 Mustangs and then the companies led by Second Lieutenant Suwarno attacking the convoy and Major Soeyoto also joined,in this ambush the Indonesian forces succeeded to inflicted heavy casualties and many of the allied supplies was destroyed,unfortunately the Suwarno and Soeyoto was killed after dueled with Gurkha's and Japanese POW's.

### Siege on Fort Williem

After the British was retreated and suffered counter-attacks the British companies in Ambarawa also get encirclement and blockade in Fort Williem,Ambarawa,at this blockade the British was trapped lasted four days four night and they suffered lack of foods and supplies.

## Aftermath

Just three days after the victory, Soedirman was promoted to major general and his election as Commander of the Armed Forces, retroactive to 12 November, was confirmed, succeeding Oerip Soemohardjo, the ad interim chief for the forces, who was appointed chief of staff.
The Palagan Ambarawa Monument in Ambarawa was erected in memory of the battle. The battle's anniversary is also celebrated nationwide as Indonesian Army Day (Hari Juang Kartika TNI Angkatan Darat), a day of celebration of the first ever victory of the young army in the Indonesian National Revolution.