Battle of Timor The Battle of Timor occurred in Portuguese Timor and Dutch Timor during the Second World War . Japanese forces invaded the island on 20 February 1942 and were resisted by a small , under - equipped force of Allied military personnel — known as Sparrow Force — predominantly from Australia , United Kingdom , and the Netherlands East Indies . Following a brief but stout resistance , the Japanese succeeded in forcing the surrender of the bulk of the Allied force after three days of fighting , however several hundred Australian commandos continued to wage an unconventional raiding campaign . They were resupplied by aircraft and vessels , based mostly in Darwin , Australia , about to the southeast , across the Timor Sea . During the subsequent fighting the Japanese suffered heavy casualties , but they were eventually able to contain the Australians . The campaign lasted until 10 February 1943 , when the final remaining Australians were evacuated , making them the last Allied land forces to leave South East Asia , following the Japanese offensives of 1941 – 1942 . As a result , an entire Japanese division was tied up on Timor for more than six months , preventing its deployment elsewhere . Although Portugal was not a combatant , many East Timorese civilians and Portuguese European colonists fought with the Allies , or provided food , shelter and other assistance . Some Timorese continued a resistance campaign following the Australian withdrawal . For this , they paid a heavy price and tens of thousands of Timorese civilians died as a result of the Japanese occupation , which lasted until the end of the war in 1945 . Background . By late - 1941 , the island of Timor was divided politically between two colonial powers : the Portuguese in the east with a capital at Dili , and the Dutch in the west with an administrative centre at Kupang . A Portuguese enclave at Ocussi was also within the Dutch area . The Dutch defence included a force of 500 troops centred on Kupang , while the Portuguese force at Dili numbered just 150 . In February the Australian and Dutch governments had agreed that in the event Japan entered the Second World War on the Axis side , Australia would provide aircraft and troops to reinforce Dutch Timor . Portugal — under pressure from Japan — maintained their neutrality however . As such , following the Japanese attack on Pearl Harbor , a small Australian force — known as Sparrow Force — arrived at Kupang on 12 December 1941 . Meanwhile , two similar forces , known as Gull Force and Lark Force , were sent by the Australians to reinforce Ambon and Rabaul . Sparrow Force was initially commanded by Lieutenant Colonel William Leggatt , and included the 2 / 40th Battalion , a commando unit — the 2nd Independent Company — under Major Alexander Spence , and a battery of coastal artillery . There were in total around 1 , 400 men . The force reinforced Royal Netherlands East Indies Army troops under the command of Lieutenant Colonel Nico van Straten , including the Timor and Dependencies Garrison Battalion , a company from the VIII Infantry Battalion , a reserve infantry company , a machine - gun platoon from the XIII Infantry Battalion and an artillery battery . 12 Lockheed Hudson light bombers of No . 2 Squadron , Royal Australian Air Force ( RAAF ) . Sparrow Force was initially deployed around Kupang , and the strategic airfield of Penfui in the south - west corner of the island , although other units were based at Klapalima , Usapa Besar and Babau , while a supply base was also established further east at Champlong . Up to this point , the government of Portugal had declined to co - operate with the Allies , relying on its claim of neutrality and plans to send an 800 - strong force from Mozambique to defend the territory in the event of any Japanese invasion . However , this refusal left the Allied flank severely exposed , and a 400 - man combined Dutch - Australian force subsequently occupied Portuguese Timor on 17 December . In response , the Portuguese Prime - Minister , António de Oliveira Salazar , protested to the Allied governments , while the governor of Portuguese Timor declared himself a prisoner in order to preserve the appearance of neutrality . No resistance was offered by the small Portuguese garrison however , and the local authorities tacitly co - operated , while the population itself generally welcomed the Allied force . Most of the Dutch troops and the whole of the 2 / 2nd Independent Company , were subsequently transferred to Portuguese Timor and they were distributed in small detachments around the territory . Meanwhile , the Portuguese and the British governments reached an agreement that established the withdrawal of the Allied forces from Portuguese Timor , in exchange for the sending , by Portugal , of a military force to replace the Dutch and Australian forces . The Portuguese military force sails from Lourenço Marques , Mozambique heading for Timor on the 26 January 1942 , aboard the transport ship " João Belo " , escorted by the aviso NRP " Gonçalves Zarco " . Prevented from landing by the Japanese on the 7 February , the Portuguese expedition would be forced to return , heading first to Singapore and then to Portuguese India . Prelude . In January 1942 , the Allied forces on Timor became a key link in the so - called " Malay Barrier " , defended by the short - lived American - British - Dutch - Australian Command under the overall command of General Sir Archibald Wavell . Additional Australian support staff arrived at Kupang on 12 February , including Brigadier William Veale , who had been made the Allied commanding officer on Timor . By this time , many members of Sparrow Force — most of whom were unused to tropical conditions — were suffering from malaria and other illnesses . The airfield at Penfui in Dutch Timor also become a key air link between Australia and American forces fighting in the Philippines under General Douglas MacArthur . Penfui came under attack from Japanese aircraft on 26 and 30 January 1942 , however the raids were hampered by the British anti - aircraft gunners and , to a lesser degree , by P - 40 fighter s of the 33rd Pursuit Squadron , United States Army Air Forces , 11 of which were based in Darwin . Later , another 500 Dutch troops and the British 79th Light Anti - Aircraft Battery arrived to reinforce Timor , while an additional Australian - American force was scheduled to arrive in February . Meanwhile , Rabaul fell to the Japanese on 23 January , followed by Ambon on 3 February , and both Gull Force and Lark Force were destroyed . Later , on 16 February , an Allied convoy carrying reinforcements and supplies to Kupang — escorted by the heavy cruiser , the destroyer , and the sloop s and — came under intense Japanese air attack and was forced to return to Darwin without landing . The reinforcements had included an Australian pioneer battalion — the 2 / 4th Pioneer Battalion — and the 49th American Artillery Battalion . Sparrow Force could not be reinforced further and as the Japanese moved to complete their envelopment of the Netherlands East Indies , Timor was seemingly the next logical target . Battle . Japanese invasion of Portuguese Timor , 19 – 20 February 1942 . On the night of 19 / 20 February 1 , 500 troops from the Imperial Japanese Army ' s 228th Regimental Group , 38th Division , XVI Army , under the command of Colonel Sadashichi Doi , began landing in Dili . Initially the Japanese ships were mistaken for vessels carrying Portuguese reinforcements , and the Allies were caught by surprise . Nevertheless , they were well - prepared , and the garrison began an orderly withdrawal , covered by the 18 - strong Australian Commando No . 2 Section stationed at the airfield . According to Australian accounts of the resistance to the Japanese landings at Dili , the commandos had killed an estimated 200 Japanese in the first hours of the battle , although the Japanese army recorded its casualties as including only seven men . Native accounts of the landings support the Australian claims , however . Another group of Australian commandos , No . 7 Section , was less fortunate , driving into a Japanese roadblock by chance . Despite surrendering , it is believed that all but one were massacred by the Japanese . Outnumbered , the surviving Australians then withdrew to the south and to the east , into the mountainous interior . Van Straten and 200 Dutch East Indies troops headed southwest toward the border . Japanese landings in Dutch Timor , 19 – 20 February 1942 . On the same night , Allied forces in Dutch Timor also came under extremely intense air attacks , which had already caused the small RAAF force to be withdrawn to Australia . The bombing was followed up by the landing of the main body of the 228th Regimental Group — two battalions totalling around 4 , 000 men — on the undefended southwest side of the island , at the Paha River . Five Type 94 tankettes were landed to support the Japanese infantry , and the force advanced north , cutting off the Dutch positions in the west and attacking the 2 / 40th Battalion positions at Penfui . A Japanese company thrust north - east to Usua , aiming to cut off the Allied retreat . In response Sparrow Force HQ was immediately moved further east , towards Champlong . Leggatt ordered the destruction of the airfield , but the Allied line of retreat towards Champlong had been cut off by the dropping of about 300 Japanese marine paratroopers , from the 3rd Yokosuka Special Naval Landing Force , near Usua , east of Kupang . Sparrow Force HQ moved further eastward , and Leggatt ' s men launched a sustained and devastating assault on the paratroopers , culminating in a bayonet charge . By the morning of 23 February , the 2 / 40th Battalion had killed all but 78 of the paratroopers , but had been engaged from the rear by the main Japanese force once again . With his soldiers running low on ammunition , exhausted , and carrying many men with serious wounds , Leggatt accepted a Japanese invitation to surrender at Usua . The 2 / 40th Battalion had suffered 84 killed and 132 wounded in the fighting , while more than twice that number would die as prisoners of war during the next two and a half years . Veale and the Sparrow Force HQ force — including about 290 Australian and Dutch troops — continued eastward across the border , to link up with the 2 / 2 Independent Company . Australian commandos continue to resist , February – August 1942 . By the end of February , the Japanese controlled most of Dutch Timor and the area around Dili in the northeast . However , they could not move into the south and east of the island without fear of attack . The 2 / 2nd Independent Company was specially trained for commando - style , stay behind operations and it had its own engineers and signalers , although it lacked heavy weapons and vehicles . The commandos were hidden throughout the mountains of Portuguese Timor , and they commenced raids against the Japanese , assisted by Timorese guides , native carriers and mountain ponies . Although Portuguese officials — under Governor Manuel de Abreu Ferreira de Carvalho — remained officially neutral and in charge of civil affairs , both the Portuguese and the indigenous East Timorese were usually sympathetic to the Allies , who were able to use the local telephone system to communicate among themselves and to gather intelligence on Japanese movements . However , the Allies initially did not have functioning radio equipment and were unable to contact Australia to inform them of their continued resistance . Doi sent the Australian honorary consul , David Ross , also the local Qantas agent , to find the commandos and pass on a demand to surrender . Spence responded : " " Surrender ? Surrender be fucked ! " " Ross gave the commandos information on the disposition of Japanese forces and also provided a note in Portuguese , stating that anyone supplying them would be later reimbursed by the Australian government . In early March , Veale and Van Straten ' s forces linked up with the 2 / 2nd Company . A replacement radio — nicknamed " Winnie the War Winner " — was cobbled together and contact was made with Darwin . By May , Australian aircraft were dropping supplies to the commandos and their allies . The Japanese high command sent a highly - regarded veteran of the Malayan campaign and the Battle of Singapore , a major known as the " Tiger of Singapore " ( or " Singapore Tiger " ; his real name is unknown ) , to Timor . On 22 May , the " Tiger " — mounted on a white horse — led a Japanese force towards Remexio . An Australian patrol , with Portuguese and Timorese assistance , staged an ambush and killed four or five of the Japanese soldiers . During a second ambush , an Australian sniper shot and killed the " Tiger " . Another 24 Japanese soldiers were also killed , and the force retreated to Dili . On 24 May , Veale and Van Straten were evacuated from the south east coast by an RAAF Catalina and Spence was appointed commanding officer , after being promoted to Lieutenant Colonel . On 27 May , Royal Australian Navy ( RAN ) launches successfully completed the first supply and evacuation missions to Timor . In June , General Douglas MacArthur — now the Supreme Allied Commander in the South West Pacific Area — was advised by General Thomas Blamey — Allied land force commander — that a full - scale Allied offensive in Timor would require a major amphibious assault , including at least one infantry division ( at least 10 , 000 personnel ) . Because of this requirement and the overall Allied strategy of recapturing areas to the east , in New Guinea and the Solomon Islands , Blamey recommended that the campaign in Timor should be sustained for as long as possible , but not expanded . This suggestion was ultimately adopted . Relations between Ferreira de Carvalho and the Japanese deteriorated . His telegraph link with the Portuguese Government in Lisbon was cut . In June 1942 , a Japanese official complained that the Governor had rejected Japanese demands to punish Portuguese officials and Timorese and civilians who had assisted the " invading army " ( the Australians ) . On 24 June , the Japanese formally complained to Lisbon , but did not take any action against Ferreira de Carvalho . Meanwhile , Doi once again sent Ross with a message , complimenting Sparrow Force on its campaign so far , and again asking that it surrender . The Japanese commander drew a parallel with the efforts of Afrikaner commandos of the Second Boer War and said that he realized it would take a force 10 times that of the Allies to win . Nevertheless Doi said he was receiving reinforcements , and would eventually assemble the necessary units . This time Ross did not return to Dili , and he was evacuated to Australia on 16 July . Japanese counter - offensive , August 1942 . In August , the Japanese 48th Division — commanded by Lieutenant General Yuitsu Tsuchihashi — began arriving from the Philippines and garrisoned Kupang , Dili and Malacca , relieving the Ito detachment . Tsuchihashi then launched a major counter - offensive in an attempt to push the Australians into a corner on the south coast of the island . Strong Japanese columns moved south — two from Dili and one from Manatuto on the northeast coast . Another moved eastward from Dutch Timor to attack Dutch positions in the central south of the island . The offensive ended on 19 August when the main Japanese force was withdrawn to Rabaul , but not before they secured the central town of Maubisse and the southern port of Beco . The Japanese were also recruiting significant numbers of Timorese civilians , who provided intelligence on Allied movements . Meanwhile , also in late - August , a parallel conflict began when the Maubisse rebelled against the Portuguese . During September the main body of the Japanese 48th Division began arriving to take over the campaign . The Australians also sent reinforcements , in the form of the 450 - strong 2 / 4th Independent Company — known as " Lancer Force " — which arrived on 23 September . The destroyer ran aground at the southern port of Betano while landing the 2 / 4th , and had to be abandoned after it came under air attack . The ship ' s crew was safely evacuated by and on 25 September 1942 and the ship destroyed by demolition charges . On 27 September , the Japanese mounted a thrust from Dili towards the wreck of " Voyager " , but without any significant success . By October , the Japanese had succeeded in recruiting significant numbers of Timorese civilians , who suffered severe casualties when used in frontal assaults against the Allies . The Portuguese were also being pressured to assist the Japanese , and at least 26 Portuguese civilians were killed in the first six months of the occupation , including local officials and a Catholic priest . On 1 November , the Allied high command approved the issuing of weapons to Portuguese officials , a policy which had previously been carried out on an informal basis . At around the same time , the Japanese ordered all Portuguese civilians to move to a " neutral zone " by 15 November . Those who failed to comply were to be considered accomplices of the Allies . This succeeded only in encouraging the Portuguese to cooperate with the Allies , whom they lobbied to evacuate some 300 women and children . Spence was evacuated to Australia on 11 November , and the 2 / 2nd commander , Major Bernard Callinan was appointed Allied commander in Timor . On the night of 30 November - 1 December , the Royal Australian Navy mounted a major operation to land fresh Dutch troops at Betano , while evacuating 190 Dutch soldiers and 150 Portuguese civilians . The launch was used to ferry the passengers between the shore and two corvette s , and . However , " Armidale " — carrying the Dutch reinforcements — was sunk by Japanese aircraft and almost all of those on board were lost . Also during November , the Australian Army ' s public relations branch arranged to send the Academy Award - winning documentary filmmaker Damien Parer , and a war correspondent named Bill Marien , to Timor . Parer ' s film , " Men of Timor " , was later greeted with enthusiasm by audiences in Allied countries . Australian withdrawal , December 1942 – February 1943 . By the end of 1942 , the chances of the Allies re - taking Timor were remote , as there were now 12 , 000 Japanese troops on the island and the commandos were coming into increasing contact with the enemy . The Australian chiefs of staff estimated that it would take at least three Allied divisions , with strong air and naval support to recapture the island . Indeed , as the Japanese efforts to wear down the Australians and to separate them from their native support became more effective , the commandos had found their operations becoming increasingly untenable . Likewise , with the Australian Army fighting a number of costly battles against the Japanese beachheads around Buna in New Guinea , there were currently insufficient resources to continue operations in Timor . As such from early December Australian operations on Timor would be progressively wound down . On 11 – 12 December , the remainder of the original Sparrow Force — except for a few officers — was evacuated with Portuguese civilians , by the Dutch destroyer HNLMS " Tjerk Hiddes " . Meanwhile , in the first week of January the decision was made to withdraw Lancer Force . On the night of 9 / 10 January 1943 , the bulk of the 2 / 4th and 50 Portuguese were evacuated by the destroyer . A small intelligence team known as S Force was left behind , but its presence was soon detected by the Japanese . With the remnants of Lancer Force , S Force made its way to the eastern tip of Timor , where the Australian - British Z Special Unit was also operating . They were evacuated by the American submarine on 10 February . Forty Australian commandos were killed during this phase of the fighting , while 1 , 500 Japanese were believed to have died . Aftermath . Overall , while the campaign on Timor had little strategic value , the Australian commandos had prevented an entire Japanese division from being used in the earlier phases of the New Guinea campaign while at the same time inflicting a disproportionate level of casualties on them . In contrast to those in Java , Ambon or Rabaul , Australian operations in Timor had been far more successful , even if it was also largely a token effort in the face of overwhelming Japanese strength . Likewise , they had proved that in favorable circumstances , unconventional operations could be both versatile and more economic than conventional operations , for which the resources were not available to the Allies at that time . Regardless , this success came at a high price and included the deaths of between 40 , 000 to 70 , 000 Timorese and Portuguese civilians during the Japanese occupation . Total Allied casualties included around 450 killed , while more the 2 , 000 Japanese were believed to have died in the fighting . Ultimately , Japanese forces remained in control of Timor until their surrender in August 1945 , following the destruction of Hiroshima and Nagasaki . On 5 September 1945 , the Japanese commanding officer met Portuguese Governor Manuel de Abreu Ferreira de Carvalho , effectively returning power to him and placing the Japanese forces under Portuguese authority . On 11 September , the Australian Timorforce arrived in Kupang harbor and accepted the surrender of all Japanese forces on Timor from the senior Japanese officer on Timor , Col . Kaida Tatsuichi of the 4th Tank Regiment . The commander of the Timorforce , Brig . Lewis Dyke , a senior diplomat , W . D . Forsyth , and " as many ships as possible " were dispatched to Dili , arriving on 23 September . Ceremonies were then held with Australians , Portuguese and other local residents . Australian troops then supervised the disposal of arms by Japanese work parties before returning to West Timor for the surrender of the commander of the 48th Division , Lt . Gen . Yamada Kunitaro . On 27 September , a Portuguese naval and military force of more than 2 , 000 troops arrived to an impressive ceremony of welcome by the Timorese people . These troops included three engineering companies along with substantial supplies of food and construction materials for the reconstruction of Timor .