View source for Battle of North Borneo

{{short description|1945 battle of World War II}}
{{good article}}
{{Use dmy dates|date=July 2024}}
{{Infobox military conflict
|conflict = Battle of North Borneo
|partof = [[Pacific War|Pacific theatre]] of the [[World War II|Second World War]]
|image = [[File:Soldiers from the 2-43rd Battalion patrolling on Labuan (AWM photo 109462).jpg|250px]]
|caption = Members of a patrol from 'A' Company, Australian 2/43rd Battalion, disembark from a boat and walk along a large fallen tree, as they move inland to investigate reports of Japanese activity.
|date = 10 June – 15 August 1945
|place = [[North Borneo]] (present-day [[Sabah]] and [[Brunei]])
|result = Allied victory
|combatant1 = {{flag|Australia}} <br /> {{flag|United States|1912}}
|combatant2 = {{flagcountry|Empire of Japan}}
|commander1 = {{flagicon|Australia}} [[George Wootten]] <br /> {{flagicon|Australia}} [[Selwyn Porter]]<br /> {{flagicon|Australia}} [[Victor Windeyer]]
|commander2 = {{flagicon|Empire of Japan}} [[Baba Masao]] <br/> {{flagicon|Empire of Japan}} [[Taijiro Akashi]]
|units1 = {{flagicon|Australia}} [[9th Division (Australia)|9th Division]]
*[[20th Brigade (Australia)|20th Brigades]]
*[[24th Brigade (Australia)|24th Brigades]]
{{flagicon|United States|1912}} 727th Amphibian Tractor Battalion
{{flagicon|United States|1912}} 593rd Engineer Boat and Shore Regiment
|units2 = {{flagicon|Empire of Japan}} [[Japanese Thirty-Seventh Army|Thirty-Seventh Army]]
* [[56th Independent Mixed Brigade|56th Mixed Brigade]]
|strength1 = ≈29,000–30,000 men
|strength2 = ≈8,800 men (Allied estimate)
|casualties1 = 114 killed or died of wounds <br /> 221 wounded
|casualties2 = At least 1,234 killed <br /> 130 captured
|campaignbox = {{Campaignbox Borneo Campaign (1945)}}<br>{{Campaignbox South West Pacific theatre}}
|campaign = [[Borneo Campaign (1945)]]
}}

The '''Battle of North Borneo''' took place during the [[World War II|Second World War]] between [[Allies of World War II|Allied]] and Japanese forces. Part of the wider [[Borneo Campaign (1945)|Borneo campaign]] of the [[Pacific War]], it was fought between 10 June and 15 August 1945 in [[North Borneo]] (later known as [[Sabah]]). The battle involved a series of amphibious landings by Australian forces on various points on the mainland around [[Brunei Bay]] and upon islands situated around the bay. Japanese opposition to the landings was sporadic initially, although as the campaign progressed a number of considerable clashes occurred and both sides suffered significant casualties, although major combat was largely restricted to [[Battle of Labuan|Labuan]] and around [[Battle of Beaufort (1945)|Beaufort]]. On the mainland, while Allied conventional operations focused largely on the coastal areas around Brunei Bay, [[guerrilla]] forces consisting of [[Dayak people|Dayak tribesmen]] and small numbers of Allied personnel from the [[Services Reconnaissance Department]] fought an unconventional campaign in the interior. The Allies were successful in seizing control of the region. Nevertheless, many of the strategic gains that possession of North Borneo provided were ultimately negated by the sudden conclusion of the war in August 1945.

==Background==
===Strategic situation and planning===
Codenamed [[Operation Oboe|Operation Oboe Six]],<ref name=AWM/> the battle was part of the second phase of the [[Allies of World War II|Allied]] operations to capture the island of [[Borneo]].  North Borneo had been occupied by troops from the [[Imperial Japanese Army]] since early 1942 following the  [[Borneo campaign (1942)|Japanese invasion of Borneo]]; prior to this the area had been a British territorial possession.<ref>{{harvnb|Shindo|2016|p=67}}</ref><ref>{{harvnb|Pratten|2016|pp=298–299}}</ref> Following its occupation, the area's oil resources had been exploited for the Japanese war effort. The island's population had also been subjected to [[Japanese occupation of British Borneo|harsh occupation policies]].{{sfn|Long|1963|p=453}}{{sfn|Rottman|2002|p=258}} This had led to a [[Jesselton Revolt|revolt at Jesselton]] in late 1943, which was suppressed by the Japanese with heavy civilian casualties.{{sfn|Gin|1999|p=56}}

The first stage of the Allied campaign in Borneo had begun in May 1945 when a [[brigade]]-sized force had been put ashore on [[Battle of Tarakan (1945)|Tarakan]], on the north-eastern side of Borneo.<ref name=Coulthard252>{{harvnb|Coulthard-Clark|1998|p=252}}</ref> The operation in North Borneo was planned by General [[Douglas MacArthur]]'s [[South West Pacific Area (command)|South West Pacific Area]] command. Designed with three phases—preparatory bombardment, forced landings, and an advance—the objective of the Allied operation was to establish "an advanced fleet base" for the [[British Pacific Fleet]] in Brunei Bay, which offered the Allies a deep-water port, to enable subsequent naval operations.{{sfn|Odgers|1968|p=466}} Further objectives included capturing the vast oil and rubber supplies available in the area and re-establishing British civil administration.<ref name=Keogh444/> It was also intended that [[Labuan]] would be secured to control the entrance to Brunei Bay, and would be developed as an airbase.{{sfn|Odgers|1968|p=466}} In the planning phase of the operation, the Allied high commands differed in their opinions about the necessity of securing Brunei, with the British [[Chiefs of Staff Committee]] believing it would take too long to develop the area for it to be developed for it to be used in operations. They were also concerned that it would divert the British Pacific Fleet from the main theatre of operations off Japan and instead favoured establishing a fleet base in the [[Philippines in World War II|Philippines]]. The United States [[Joint Chiefs of Staff]], however, approved the operation believing that it could support future operations in south-east Asia.{{sfn|Long|1963|pp=50–51}}

[[File:N borneo ops 1945.jpg|300px|thumb|right|A map showing the movements of the main Australian infantry units in North Borneo]]

In preparation for the landings, commencing in March, the Allied [[Services Reconnaissance Department]] (also known as Special Operations Australia) began [[Operation Agas]] in North Borneo, and [[Operation Semut]] in Sarawak; these were clandestine operations to gather information and organise local [[Dayak people|Dayak tribesmen]] to carry out [[guerrilla]] operations following the main landings.<ref>{{harvnb|Pratten|2016|p=307}}</ref> Ultimately, five Allied parties would be inserted into Borneo as part of Operation Agas, while four were deployed under Semut.<ref name=Pratten307-309>{{harvnb|Pratten|2016|pp=307–309}}</ref> Preliminary aerial bombardment of northern Borneo by Australian and US aircraft began on 3 May, before being concentrated on the main landing areas on 5 June. Meanwhile, [[minesweeper]]s began to clear [[sea lines of communication]] for the large Allied naval task force that was assigned to support the operation. This force was designated as Task Force 78.1 and consisted of Australian and US warships, under the command of Rear Admiral [[Forrest B. Royal]].<ref name=Pratten300-301>{{harvnb|Pratten|2016|pp=300–301}}</ref> Initially, the Allies planned to launch operations in North Borneo in late May, but shipping shortages delayed moving the assault troops to their staging base on [[Morotai Island]]  and resulted in the operation being delayed until early June.{{sfn|Odgers|1968|p=466}}

===Opposing forces===
A total of 29,000–30,000 men were committed by the Allies to secure North Borneo,{{#tag:ref|Odgers 1988, p. 183 provides the figure of 30,000 men, while Coulthard-Clark 1998, p. 252 provides the figure of 29,000. Long (1963), p. 459 provides the figure of 29,361 and breaks this down as: 14,079 men from the 9th Division; 3,726 corps support troops; 4,730 base sub-area troops, 5,729 Royal Australian Air Force personnel and 1,097 American and British personnel.|group=Note}} with the majority of the ground forces being provided by the [[9th Division (Australia)|Australian 9th Division]], under the command of Major General [[George Wootten]]. The 9th Division consisted of three brigades—the [[20th Brigade (Australia)|20th]], [[24th Brigade (Australia)|24th]] and [[26th Brigade (Australia)|26th Brigades]]—however, at the time of the North Borneo operations, the 26th was engaged at Tarakan having been detached from the division in May 1945, so only two brigades were allocated to operations in North Borneo.<ref name=Coulthard252/> Part of the all-volunteer [[Second Australian Imperial Force]], the 9th Division was a veteran formation, having previously served in North Africa, the Middle East and New Guinea. Prior to the Borneo campaign, the division had been resting and reorganising on the [[Atherton Tablelands]] in Queensland.{{sfn|McKenzie-Smith|2018|pp=2047–2049}}  The division had experienced a high turn over in personnel following its service in the [[Huon Peninsula campaign]] as soldiers were medically discharged or transferred to other units.{{sfn|Johnston|2002|p=186}} In addition to the Australian ground troops, naval support was provided by the [[United States Navy]] and [[Royal Australian Navy]] and aerial support from the [[United States Army Air Force]]'s [[Thirteenth Air Force]], the [[United States Marine Corps]], and elements of the [[Royal Australian Air Force]]'s [[Australian First Tactical Air Force|1st Tactical Air Force]].<ref>{{harvnb|Odgers|1988|p=183}}</ref><ref name=Long458>{{harvnb|Long|1963|p=458}}</ref> Two [[United States Army]] units, the 727th Amphibian Tractor Battalion who manned the [[Landing Vehicle Tracked|LVTs]] and the 593rd Engineer Boat and Shore Regiment's Boat Battalion, were also attached to the Australians.<ref name=Keogh444>{{harvnb|Keogh|1965|p=444}}</ref>

Meanwhile, Allied intelligence estimated that there were approximately 31,000 Japanese troops on Borneo,<ref name=Long456>{{harvnb|Long|1963|p=456}}</ref> with about 8,800 of these in North Borneo.<ref>{{harvnb|Keogh|1965|p=447}}</ref> The Japanese [[Japanese Thirty-Seventh Army|Thirty-Seventh Army]],{{#tag:ref|A Japanese "army" of World War II was equivalent to an Allied [[corps]], and usually commanded between two and four [[Division (military)|divisions]].{{sfn|Rottman|2005|p=23}}|group=Note}} led by Lieutenant-General [[Masao Baba]],{{sfn|Bullard|2016|p=43}} was tasked with defending the area, and was headquartered in [[Jesselton]].{{sfn|Keogh|1965|p=434}} The main Japanese units in the vicinity included elements of the [[56th Independent Mixed Brigade]], consisting of six [[battalion]]s (the 366th to the 371st), along with another independent battalion.<ref name=Long456/> This brigade was commanded by Major General [[Taijiro Akashi]].{{sfn|Dredge|1998|p=574}} It had been raised in Japan during the second half of 1944 and arrived in Borneo late that year as the area's garrison troops were reorganised for defence against future Allied landings.{{sfn|Shindo|2016|pp=68–70}} By mid-1945, the brigade had been heavily depleted by its overland movement from the north-eastern part of Borneo prior to the Allied landings and was at around half strength; its troops were largely inexperienced, lightly equipped and were suffering from poor morale.<ref>{{harvnb|Pratten|2016|pp=303–304}}</ref> Japanese air power in the region had been heavily depleted and, except in Java and Sumatra, was ineffective,{{sfn|Keogh|1965|p=434}} although there were small numbers of aircraft at [[Keningau]] and [[Kuching]].{{sfn|Odgers|1968|pp=473 & 475}}

==Battle==
===Labuan===
{{main|Battle of Labuan}}
[[File:Australian troops landing on Labuan, 1945.JPG|thumb|left|Australian troops from the [[24th Brigade (Australia)|24th Brigade]] landing on Labuan on 10 June 1945.]]
Two main landings were undertaken by the Australians in North Borneo on 10 June. After concentrating at Morotai Island in May, where complex landing rehearsals were undertaken,<ref name=Pratten300-301/> the assault force, consisting of 85 ships—mainly from the US Navy—departed in early June, preceded by minesweepers and survey vessels, as well as the naval attack group.{{sfn|Gill|1968|pp=638–640}} The first landing was made when troops from two battalions of Brigadier [[Selwyn Porter]]'s 24th Brigade—the [[2/28th Battalion (Australia)|2/28th]] and [[2/43rd Battalion (Australia)|2/43rd Battalions]]—[[Battle of Labuan|landed on Labuan Island]] with a [[Squadron (army)|squadron]] of [[Matilda II|Matilda tank]]s from the [[2/9th Armoured Regiment (Australia)|2/9th Armoured Regiment]].<ref name=Coulthard252/> The 24th Brigade's third battalion, 2/32nd Battalion, was placed in divisional reserve for the initial landing.<ref name=Keogh448>{{harvnb|Keogh|1965|p=448}}</ref> The attack was preceded by a heavy naval bombardment from cruisers, mortar and rocket ships, and attacks by eight [[Consolidated Liberator|Liberator]] heavy bomber squadrons which used anti-personnel bombs to target Japanese troops around the intended beachheads.{{sfn|Odgers|1968|p=470}} With this support, the main Allied landings were largely unopposed as the Japanese defenders had withdrawn from the beaches on the peninsula and Muara Island had been abandoned completely.  At Labuan, the Australian troops came ashore near Victoria and, supported by a heavy artillery and naval gunfire support, the two battalions drove towards the airfield. Light opposition was overcome and the town and airfield were secured late on the first day, after minor clashes with Japanese outposts and troops fighting amongst the aircraft dispersal bays. Meanwhile, the [[2/11th Commando Squadron (Australia)|2/11th Commando Squadron]] provided flank support to the west.{{sfn|Pratten|2016|p=301}}

Despite the initial progress the fighting on Labuan intensified during this time as the Japanese defenders retreated inland to a heavily fortified position known as "the Pocket" and attempted to hold the Australians along the dense jungle ridges and thick swamps. The [[2/12th Commando Squadron (Australia)|2/12th Commando Squadron]] was brought ashore from divisional reserve on 12 June and was given the task of clearing the outlying areas of resistance that had been bypassed during the initial advance on the island,<ref name="Long472"/> By 14 June, the Australians had secured the island, apart from those Japanese contained within the Pocket.{{sfn|Pratten|2016|p=302}} Despite considerable artillery and [[Tank|armoured]] support, a [[Company (military unit)|company]]-level attack by the 2/28th Battalion was turned back on 14 June, and as a result further preparatory fires were called upon to soften up the Japanese defences.<ref name=Long472>{{harvnb|Long|1963|p=472}}</ref>

At this stage of the war, Australian commanders were under strict orders to limit their casualties, and "avoid unnecessary risks", utilising fire support where possible to reduce Japanese defences prior to attacking.{{sfn|Pratten|2016|p=302}} Commencing on 17 June, an intense three day naval and aerial bombardment was laid down in an effort to reduce the Japanese defences. Meanwhile, 100 Japanese attacked the Australian brigade's maintenance area and the airfield before the Australians launch a renewed attack on 21 June.<ref name=Coulthard252/><ref>{{harvnb|Pratten|2016|p=302}}</ref> At this time, two companies of [[infantry]] from the 2/28th Battalion assaulted the Japanese position. Supported by indirect fire support from sea and air, and direct fire support from tanks and [[flamethrower]]s, the Australians overwhelmed the Japanese defenders and cleared the remaining resistance from Labuan. After the battle 180 Japanese dead were counted, bringing the total killed during the fighting on Labuan to 389. Against this the Australians suffered 34 killed and 93 wounded.<ref>{{harvnb|Odgers|1988|pp=183–184}}</ref><ref>{{harvnb|Long|1963|p=475}}</ref>

[[File:2-13th Infantry Battalion patrol around Miri in 1945 (AWM photo 115189).jpg|thumb|right|Troops from the 2/13th Battalion patrolling around Miri, August 1945]]

===Brunei and Muara Island===

The second Allied landing that took place on 10 June, consisted of two battalions of Brigadier [[Victor Windeyer]]'s 20th Brigade—[[2/15th Battalion (Australia)|2/15th]] and [[2/17th Battalion (Australia)|2/17th Battalions]]—landing at [[Muara Besar Island|Muara Island]] and on the mainland peninsula north of [[Brooketon]], supported by a second squadron of Matildas from the 2/9th Armoured Regiment.<ref name=Coulthard252/> The 20th Brigade's third battalion, the [[2/13th Battalion (Australia)|2/13th]], was held back in brigade reserve.<ref name=Keogh448/> Meanwhile, in the interior, Dayak tribesmen supported by Allied operatives commenced their guerrilla campaign on 9 June. Lightly armed, and with only limited training, these guerrillas sought to harass the withdrawing Japanese, while avoiding decisive engagement. In this role, they met with some success, but were in some cases forced to withdraw in the face of heavy opposition.{{sfn|Pratten|2016|pp=308–309}} The troops that had landed near Brooketon on the mainland advanced on Brunei, which was captured on 13 June by the 2/17th Battalion after several minor section and platoon level actions over several days.{{sfn|Pratten|2016|p=302}} The 2/15th, which had earlier secured Muara Island, secured Limbang on 18 June, advancing by landing craft up the river in the south-west of Brunei Bay.{{sfn|Pratten|2016|p=303}} The two 20th Brigade battalions were now joined by the 2/13th Battalion, which had conducted an unopposed landing at [[Lutong]] on 20 June, supported by [[Supermarine Spitfire|Spitfire]] and [[Curtiss P-40 Warhawk|Kittyhawk]] fighters operating from Labuan,{{sfn|Odgers|1968|p=473}} before continuing their advance down the south-western coast and then overland, passing through [[Miri, Malaysia|Miri]] and [[Seria]] on their way towards Kuching.<ref>{{harvnb|Coulthard-Clark|1998|pp=252–253}}</ref>

At Seria the Australians found the 37 oil wells ablaze, having been deliberately lit by the Japanese defenders as they withdrew, and engineers from the 2/3rd Field Company were called up to put out the fires, a task which took over three months to complete.<ref>{{harvnb|Long|1963|p=485}}</ref> [[Kuala Belait]] was reached on 24 June.{{sfn|Pratten|2016|p=302}} Having secured its objectives, the 20th Brigade then began patrolling operations, using landing craft to move quickly along the various rivers and streams that punctuated the coastline.<ref name=Keogh453>{{harvnb|Keogh|1965|p=453}}</ref> The initial priority of Japanese troops on the mainland was to withdraw inland. As a result, only minor clashes occurred, against Japanese rearguards, which were generally poorly equipped and inexperienced. Resistance and aggressiveness amongst these rearguard elements stiffened as the Australians moved beyond Miri.{{sfn|Pratten|2016|p=304}} Generally, the guerrilla forces in the interior carried out their operations separately from the conventional forces that focused mainly upon the coastal areas. However, some co-ordinated action was achieved during the campaign. During July, guerrillas assigned to Operation Semut captured Marudi, on the Barem River, as part of efforts to disrupt the Japanese withdrawal from Miri. A strong Japanese counter-attack retook the village from the lightly armed Semut operatives, after which the guerrillas linked up with conventional Australian infantry from the 2/17th Battalion to capture it once again on 15 July.{{sfn|Pratten|2016|pp=306–309}} During the course of their involvement in the campaign, the 20th Brigade's casualties were relatively light, suffering only 40 casualties.<ref>{{harvnb|Johnston|2002|p=228}}</ref> Throughout late June and into August, RAAF aircraft including [[de Havilland Mosquito|Mosquitos]] and [[Bristol Beaufighter|Beafighter]]s attacked Japanese targets throughout North Borneo, including barges, shipping, barracks and airfields, sinking an 800-ton vessel near the Tabuan River and destroying several Japanese aircraft on the ground. [[CAC Wirraway|Wirraway]]s were also used to provide tactical reconnaissance, and other fighters flew [[close air support]] sorties.{{sfn|Odgers|1968|pp=473–475}}

===Weston===
Another landing was made by Allied forces on 16 June on the mainland at [[Weston, Sabah|Weston]], in the north-eastern part of [[Brunei Bay]].<ref name=Coulthard252/> The [[2/32nd Battalion (Australia)|2/32nd Battalion]], which had previously been held back as the divisional reserve, forced its way ashore near Padas Bay. After taking Weston, patrols were sent out to [[Beaufort, Sabah|Beaufort]], which was {{convert|23|km|mi|abbr=on}} inland.<ref name=Coulthard252/> Due to the lack of roads and the indefensible nature of the railway track that led to the town, it was decided to advance along the Klias River, while a secondary force moved along the Padas River.<ref name=Keogh453/> As a part of this phase of the operation, minor landings were made at [[Mempakul]] on 19 June and at [[Sabang, Sabah|Sabang]] on 23 June by elements of the 2/43rd Battalion and the 2/11th Commando Squadron.<ref>{{harvnb|Keogh|1965|pp=453–454}}</ref> Kibidang was captured the same day by the 2/43rd, while the 2/32nd advanced further along the Padas River and the two battalions married up.<ref name=Keogh454>{{harvnb|Keogh|1965|p=454}}</ref> Following this, reinforcements in the form of two companies from the 2/28th Battalion were transferred from Labuan to take over rear area security while plans were made for the main attack on Beaufort.<ref name=Keogh454/>

[[File:Australian 2-32 Inf Bn landing at Weston (AWM image 018680).JPG|thumb|left|Troops from the Australian 2/32nd Battalion land at Weston aboard US-crewed landing vehicles]]

The Allies assessed that Beaufort, which lay on the main Japanese avenue of withdrawal, was held by between 800 and 1,000 Japanese troops seeking to keep key egress routes open.{{sfn|Pratten|2016|p=304}} On 27 June, the Australians [[Battle of Beaufort (1945)|attacked the town]].<ref name=Coulthard253>{{harvnb|Coulthard-Clark|1998|p=253}}</ref> The 2/43rd Battalion was assigned the task of the main assault, while the 2/32nd Battalion was tasked with flank protection. Despite being hamstrung by torrential downpours and unforgiving terrain, the 2/32nd Battalion secured the south bank of the Padas River, while one company from the 2/43rd was sent to take the town and another marched to the flanks, to take up ambush positions along the route that the Japanese were expected to withdraw along. The 2/28th Battalion secured the lines of communication north of the river.<ref name=Keogh454/> The resistance from the Japanese defenders was not co-ordinated and as a result the Australians had secured their objectives by nightfall. Throughout the night, however, the Japanese launched six counterattacks which eventually broke down into hand-to-hand combat. During the course of these actions, one company became isolated and the next morning, 28 June, another was sent to aid it by attacking the Japanese force from the rear. Fighting its way through numerous Japanese positions throughout the afternoon, the company reached its objective in the early evening and launched its assault, killing at least 100 Japanese defenders.<ref>{{harvnb|Long|1963|pp=479–481}}</ref><ref>{{harvnb|Odgers|1988|p=184}}</ref> It was during the course of this action that Private [[Leslie Thomas Starcevich|Tom Starcevich]], of the 2/43rd Battalion, performed the deeds for which he was later awarded the [[Victoria Cross]].<ref>{{harvnb|Johnston|2002|pp=235–236}}</ref>

By 29 June, the Japanese began to withdraw from Beaufort in small groups.<ref name=Keogh455>{{harvnb|Keogh|1965|p=455}}</ref> Elsewhere, on 1 July, the Australian [[7th Division (Australia)|7th Division]] carried out the final stage of the Allied operation to secure Borneo, [[Battle of Balikpapan (1945)|landing at Balikpapan]], on the south-east coast.<ref>{{harvnb|Coulthard-Clark|1998|p=254}}</ref> In North Borneo, Allied forces observed a brief pause while reinforcements arrived. The [[2/3rd Anti-Tank Regiment (Australia)|2/3rd Anti-tank Regiment]], being used as infantry rather than the anti-tank role for which it was intended, arrived at Weston on 3 July, where it relieved the 2/28th Battalion, which then moved on to Beaufort.<ref name=Long495>{{harvnb|Long|1963|p=495}}</ref> On 6 July the Australian advance was resumed. Due to the strategic situation, it was decided to undertake a slow and cautious advance using indirect fire to limit casualties. By 12 July the 2/32nd Battalion occupied [[Papar, Sabah|Papar]],<ref>{{harvnb|Johnston|2002|p=237}}</ref> and from there patrols were dispatched to the north and along the banks of the river as offensive operations came to an end.<ref name=Keogh455/>

==Aftermath==

Following the capture of Papar, the Australians ceased offensive actions on Borneo and the situation remained largely static until a ceasefire came into effect in mid-August.<ref name= Keogh455/>  In early August 1945, [[Atomic bombings of Hiroshima and Nagasaki|two atomic bombs were dropped on Hiroshima and Nagasaki]], and on 15 August the Japanese Emperor, [[Hirohito]], effectively announced an end to hostilities, with the formal surrender being signed on 2 September 1945.<ref>{{harvnb|Grey|2008|p=191}}</ref>  As a result of the ceasefire, [[Operation Downfall|the planned Allied invasion of Japan]] was no longer required and the strategic gains provided by the capture of North Borneo were arguably negated; this included development of Brunei Bay into a naval base, which ultimately never occurred.{{sfn|Pratten|2016|p=315}} To some extent, this has led to claims in Australia that the Oboe operations—as well as the campaigns in the [[Aitape-Wewak campaign|Aitape–Wewak region of New Guinea]] and on [[Bougainville campaign|Bougainville]] and [[New Britain campaign|New Britain]]—had been "unnecessary" and had therefore resulted in needless casualties.<ref>{{harvnb|Grey|2008|p=190}}</ref> Throughout the course of the fighting on North Borneo, the Australians lost 114 men killed or died of wounds while another 221 men were wounded. Against this, the Japanese lost at least 1,234 men, while 130 had been captured.<ref name= Coulthard253/><ref>{{harvnb|Johnston|2002|p=238}}</ref> On top of this, a further 1,800 Japanese were estimated to have been killed by the guerrilla forces operating in the interior; many of these were Japanese troops who were withdrawing inland following the conventional landings on the coast who were ambushed by guerrillas or attacked by Allied airstrikes directed by these forces. These forces also occupied large areas in Sarawak and the southern parts of North Borneo by the end of hostilities.<ref name=Long501>{{harvnb|Long|1963|p=501}}</ref><ref>{{harvnb|Pratten|2016|pp=309–310}}</ref>

[[File:Burning oil wells at Seria (Brunei) 1945.jpg|thumb|Burning oil wells at Seria]]

After the fighting was over, the Australians began the task for establishing British civil administration, rebuilding the infrastructure that had been damaged and providing for the civilians that had been displaced in the fighting.<ref name =AWM>{{cite web|url=http://www.awm.gov.au/units/place_1929.asp |archive-url=https://web.archive.org/web/20131004213935/http://www.awm.gov.au/units/place_1929.asp |archive-date=4 October 2013 |title=Battle of North Borneo| publisher=Australian War Memorial|access-date=4 September 2010}}</ref><ref name=Long496>{{harvnb|Long|1963|p=496}}</ref>  This proved to be a significant undertaking, with the 9th Division working to establish hospitals, dispensaries, and schools. Sanitation and drainage had not been provided by the Japanese, and the local population was suffering from disease and was malnourished. Infrastructure was re-built by Australian engineers, while 9th Division medical personnel provided medical aid directly to locals.{{sfn|Pratten|2016|p=311}} The {{convert|132|km|mi|adj=on}} North Borneo railway was also re-established.<ref>{{harvnb|Pratten|2016|p=314}}</ref> Houses that were destroyed in pre-invasion bombardment and later fighting were also rebuilt.<ref>{{harvnb|Long|1973|p=461}}</ref> Following the ceasefire, there were still a large number of Japanese troops in North Borneo—by October 1945 it was estimated that there were over 21,000 Japanese soldiers and civilians still in North Borneo—and the 9th Division was made responsible for organising the surrender, provisioning and protection of these personnel.<ref>{{harvnb|Long|1963|p=561}}</ref> They were also tasked with liberating the Allied civilian internees and prisoners of war that were being held at [[Batu Lintang camp]] in Kuching, Sarawak,<ref>{{harvnb|Long|1963|p=563}}</ref> and with disarming the guerrillas that had been assigned to Operations Agas and Semut.{{sfn|Pratten|2016|p=310}}

As civil administration was slowly restored, in October 1945, the [[Demobilisation of the Australian military after World War II|Australian demobilisation process]] began.<ref name=Long581>{{harvnb|Long|1963|p=581}}</ref>  Initially this process was slow as there were few troops able to relieve the Australian forces in Borneo and as such only long service personnel were released for return to Australia.<ref name=Long501/>  The 9th Division remained in North Borneo performing garrison duties until January 1946, when it was relieved by the [[32nd Indian Infantry Brigade|32nd Indian Brigade]], and subsequently disbanded.<ref>{{harvnb|Long|1963|p=565}}</ref>  For the majority of the 9th Division's personnel a return to civilian life followed, however, as part of [[British Commonwealth Occupation Force|Australia's contribution to the occupation of Japan]], a number of men from the 9th Division were transferred to the [[3rd Battalion, Royal Australian Regiment|67th Battalion]] which was being formed as part of the [[34th Brigade (Australia)|34th Brigade]].<ref>{{harvnb|Long|1963|p=577}}</ref> According to the Australian War Memorial, such was the relationship formed between the 9th Division and the civilian population of North Borneo, that the division's [[Unit Colour Patch]] was incorporated into the [[coat of arms]] of the Colony of British Borneo following the war, remaining as such until 1963, when the region was subsumed by the Malaysian state of Sabah.<ref name=AWM/>

==See also==
* [[Japanese occupation of Malaya]]

==Notes==
;Footnotes
{{Reflist|group=Note}}

;Citations
{{Reflist|2}}

==References==
{{Refbegin}}

* {{cite book |last=Bullard |first=Steven |year=2016|chapter=Chapter 2: The Emperor's Army: Military Operations and Ideology in the War Against Australia |editor1=Fitzpatrick, Georgina |editor2=McCormack, Timothy L.H. |editor3=Morris, Narrelle |chapter-url=https://books.google.com/books?id=X-TDDQAAQBAJ&pg=PA42 |publisher=[[Brill Nijhoff]] |location=Leiden, The Netherlands |title=Australia's War Crimes Trials 1945–51 |isbn=978-90-04-29205-5 |pages=27–60 }}
* {{cite book|last=Coulthard-Clark|first=Chris|title=Where Australians Fought: The Encyclopaedia of Australia's Battles|year=1998| publisher=[[Allen & Unwin]]|location=St Leonards, New South Wales|isbn=1-86448-611-2 }}
* {{cite book|editor1-last=Gin|editor1-first=Ooi Keat|title=Japanese Empire in the Tropics: Selected Documents and Reports of the Japanese Period in Sarawak Northwest Borneo 1941–1945|volume=2|date=1998|publisher=[[Ohio University Press]]|location=Athens, Ohio|isbn=0-89680-199-3|first=A.C.L.|last=Dredge|chapter=Order of Battle: Intelligence Bulletin No. 237, 15 June 1946|pages=572–598}}
* {{cite book |last=Grey |first=Jeffrey |author-link=Jeffrey Grey |year=2008 |title=A Military History of Australia |edition=3rd |publisher=[[Cambridge University Press]] |location=Melbourne, Victoria |isbn=978-0-521-69791-0 }}
* {{cite book |last=Gill |first=G Herman |author-link=G. Hermon Gill |title=Royal Australian Navy, 1942–1945 |url=https://www.awm.gov.au/collection/RCDIG1070198/ |series=[[Australia in the War of 1939–1945]]|volume=Series 2 – Navy. Volume II|year=1968 |publisher=[[Australian War Memorial]] |location=Canberra|oclc=65475}}
* {{cite book|last1=Gin|first1=Ooi Keat|title=Rising Sun Over Borneo: The Japanese Occupation of Sarawak, 1941–1945|date=1999|publisher=[[Macmillan Press]]|location=Basingstoke, Hampshire|isbn=0-333-71260-9}}
* {{cite book|last=Johnston|first=Mark|author-link=Mark Johnston (historian)|title=That Magnificent 9th: An Illustrated History of the 9th Australian Division 1940–46|year=2002|publisher=Allen & Unwin|location=Sydney, New South Wales|isbn=1-86508-654-1}}
* {{cite book|last=Keogh|first=Eustace|author-link = Eustace Graham Keogh|title=The South West Pacific 1941–45|year=1965|publisher=Grayflower Productions| location=Melbourne, Victoria|oclc=7185705}}
* {{cite book|last=Long|first=Gavin|author-link=Gavin Long|title=The Final Campaigns|series=Australia in the War of 1939–1945, Series 1 – Army, Volume VII| year=1963|publisher=Australian War Memorial|location=Canberra, Australian Capital Territory|url=https://www.awm.gov.au/collection/RCDIG1070206/|oclc=1297619}}
* {{cite book|last=Long|first= Gavin|title=The Six Years War: Australia in the 1939–45 War|publisher=Australian War Memorial and the [[Australian Government Publishing Service]]|year=1973|location=Canberra|isbn=0-642-99375-0}}
* {{cite book |last=McKenzie-Smith |first=Graham  |author-link=Graham McKenzie-Smith |year= 2018|title=The Unit Guide: The Australian Army 1939–1945, Volume 2 |publisher=Big Sky Publishing |location=Warriewood, New South Wales |isbn=978-1-925675-146}}
* {{cite book |last=Odgers |first=George |author-link=George Odgers|title=Air War Against Japan, 1943–1945 |orig-year=1957 |url=https://www.awm.gov.au/collection/RCDIG1070210/|series=Australia in the War of 1939–1945|volume=Series 3 – Air. Volume II|year=1968 |publisher=Australian War Memorial |location=Canberra|oclc=1990609}}
* {{cite book|last=Odgers|first=George|title=Army Australia: An Illustrated History|year=1988| publisher=Child & Associates| location=Frenchs Forest, New South Wales|isbn=0-86777-061-9}}
* {{cite book|last1=Pratten|first1=Garth|author-link=Garth Pratten|editor1-last=Dean|editor1-first=Peter J.|title=Australia 1944–45: Victory in the Pacific|year=2016|publisher=Cambridge University Press|location=Port Melbourne, Victoria|chapter='Unique in the History of the AIF': Operations in British Borneo|pages=298–319|isbn=978-1-107-08346-2}}
*{{cite book |last1=Rottman |first1=Gordon L. |title=Japanese Army in World War II: Conquest of the Pacific 1941-42 |date=2005 |publisher=[[Osprey Publishing|Osprey]] |location=Oxford |isbn=978-1-84176-789-5}}
* {{cite book |last=Rottman |first=Gordon L. |title=World War II Pacific Island Guide. A Geo-Military Study  |year=2002 |publisher=[[Greenwood Press]] |location=Westport |isbn=0-313-31395-4}}
* {{cite book|last1=Shindo|first1=Hiroyuki|editor1-last=Dean|editor1-first=Peter J.|title=Australia 1944–45: Victory in the Pacific|year=2016|publisher=Cambridge University Press|location=Port Melbourne, Victoria|chapter=Holding on to the Finish: The Japanese Army in the South and South West Pacific 1944–45|pages=51–76|isbn=978-1-107-08346-2}}
{{Refend}}

==External links==
{{commons category|Battle of North Borneo}}
* {{cite journal |url=http://www.awm.gov.au/journal/j37/borneo.asp |journal=Journal of the Australian War Memorial |title=Prelude to Invasion: Covert Operations Before the Re-Occupation of Northwest Borneo, 1944–45 |author=Ooi, Keat Gin |issue=37 |date=October 2002 |publisher=Australian War Memorial |access-date=14 February 2014 |issn=1327-0141}}

{{History of East Malaysia}}

{{Coord missing|Malaysia}}

{{DEFAULTSORT:North Borneo}}
[[Category:Borneo campaign]]
[[Category:North Borneo|Battle of North Borneo]]
[[Category:Conflicts in 1945]]
[[Category:Military history of Malaya during World War II]]
[[Category:South West Pacific theatre of World War II]]
[[Category:1945 in Southeast Asia|Battle of North Borneo]]
[[Category:Battles of World War II involving Australia]]
[[Category:Battles of World War II involving Japan]]
[[Category:Battles of World War II involving the United States]]
[[Category:History of Sabah]]
[[Category:Military history of Brunei]]
[[Category:June 1945 events in Asia]]
[[Category:July 1945 events in Asia]]
[[Category:August 1945 events in Asia]]