On the night of the 23rd of January, 1942, a Japanese invasion fleet carrying roughly 20,000 troops began landing around Rabaul Harbor. The Australian garrison waiting for them on the ground numbered 1,400 men. The headquarters in Melbourne that had sent them there already had it on file. There was no plan for their reinforcement or withdrawal.

Rabaul sat inside the rim of a volcanic caldera at the northeastern tip of New Britain, the largest island in the Bismarck Archipelago. The town itself was small, a colonial administrative center with a few thousand residents, a scattering of European-run plantations, mission stations, and a Chinese trading quarter along the waterfront.

 What made it worth fighting over was geography. The caldera formed a natural deep-water harbor, Simpson [music] Harbor, large enough to shelter a fleet, and protected on all sides by volcanic ridges. Two operational airstrips, Lakunai on the harbor’s edge and Vunakanau on the plateau above, gave whoever held Rabaul air reach across the Bismarck Sea, the Solomon Islands, [music] and the northern approaches to mainland Australia.

Japan needed that reach to cut the [music] Allied supply line between the United States and Australia. For Tokyo’s war planners, Rabaul was the lock on the door to the South Pacific. Lark Force had been deployed to Rabaul [music] in December 1941, built around the 2/22nd Battalion of the AIF, a handful of anti-aircraft gunners, and [music] a small detachment from the New Guinea Volunteer Rifles.

The NGVR were a different breed [music] from the rest of the garrison, planters, traders, patrol officers, men who’d lived on New Britain for years and knew the terrain, the local languages, and the tracks through the interior. There were fewer than 100 of them, but their knowledge of the island would matter later when maps became useless and the jungle became the only way out.

The rest of Lark Force were regular soldiers, most of them young, most of them fresh from training depots in Victoria. Their orders were to hold the two aerodromes and guard the harbor. Australia’s war planners understood [music] that 1,400 men with light weapons couldn’t stop a full-scale amphibious assault.

 The men were sent [music] anyway as a tripwire, a force whose only strategic value was confirming the invasion had begun. The garrison’s equipment matched its expendable [music] status. The anti-aircraft battery was small with limited ammunition stocks and no prospect of resupply. Infantry weapons were standard issue, rifles, Bren guns, grenades, but there was no armor, no heavy artillery, and no coastal [music] guns capable of engaging warships.

The two airstrips held the forces’ only air capability, a squadron of Wirraways. The Wirraway was a training aircraft, a two-seater with a fixed undercarriage and an open cockpit, designed for flight instruction at schools in rural New South Wales. It had a top speed roughly 160 km/h, >> [music] >> slower than a Japanese Zero.

Against any modern fighter, it was a coffin with wings. The pilots at Rabaul knew that before they ever took off. >> [music] >> Rabaul’s civilian population was caught between the garrison and the coming invasion. Some European women and children had been evacuated to Australia in the weeks after [music] Pearl Harbor, but the process was incomplete and disorganized.

 Missionary families, plantation [music] wives, nurses, and colonial administrators remained in the town. The Chinese community, numbering over a thousand, received no evacuation offer [music] at all. The 209 civilians who would later end up aboard the Montevideo Maru included [music] men who’d built their lives on New Britain over decades, plantation managers, government clerks, traders who’d raised families in Rabaul and had no connection to the military at all.

Their presence on that ship would come down to geography and timing, nothing else. Japanese air raids hit Rabaul for the first time on the 4th of January, 1942. Bombers came over the harbor in formation, pounding the airstrips, the fuel dumps, and the surrounding infrastructure. The Wirraway crews scrambled.

 These were men climbing into training planes to intercept combat aircraft flown by experienced pilots with superior machines in every measurable category: speed, rate of climb, armament, maneuverability. The result was predictable and the crews flew anyway. One Wirraway, during the early raids, managed to shoot down a Japanese Zero.

It was the only confirmed instance in the Pacific war of a Wirraway downing a front-line Japanese fighter. The pilot and observer pulled it off through positioning and close-range fire, getting inside the Zero’s turn radius at a range where the speed difference didn’t matter. Australian newspapers ran the story.

 It changed nothing on the ground. Within days, [music] every operational Wirraway at Rabaul was wrecked, burned on the strip, or brought down in the air. Lark Force lost its air cover, and the Japanese [music] could bomb at will on their own schedule without opposition. The raids escalated [music] through mid-January.

 Each wave targeted what the previous wave had missed. Gun positions, communication trenches, supply stores, the roads connecting the two airfields. By the 15th, garrison morale was holding, but the physical infrastructure was collapsing around it. Ammunition for the anti-aircraft guns was running low, and there was no pipeline to replace it.

The signals unit could still communicate with Melbourne, and Melbourne’s responses were consistent. Hold your position. No reinforcements available. Situation understood. The men reading those signals could do the arithmetic as well as anyone. On the 20th of January, a concentrated [music] Japanese bombing run finished the job.

The remaining anti-aircraft positions were destroyed, fuel reserves burned, the airstrips were cratered past operational use, and the last functional communication lines went down intermittently. Lark Force was now defending ground it couldn’t [music] use with weapons that were largely gone against an invasion force that signals intelligence confirmed was already at sea and closing.

Three days of silence followed. The garrison dug in and waited. The Japanese came ashore in the early hours of the 23rd. Landing craft hit multiple beaches simultaneously around Rabaul’s coastline, north, east, and along the harbor approaches. The assault force belonged to the Japanese 5th Division, supported by naval gunfire and air cover that operated without any remaining Australian opposition.

 The numbers were [music] roughly 14 to 1. The tactical situation was exactly what Melbourne’s planners had anticipated when they chose the word tripwire. Australian units engaged wherever they could make the groundwork for them. Sections of the [music] 2nd 22nd held beach positions and fired into the landing craft as the ramps dropped, inflicting casualties at [music] close range before the weight of follow-up waves pushed through.

Anti-aircraft crews who still had functional guns cranked the barrels flat and fired into the infantry advancing on their positions. Small groups fought along the ridgelines above the harbor using elevation and knowledge of the terrain to slow the advance for hours beyond the Japanese timetable. The resistance was real and it cost [music] the Japanese more than they’d planned for on a beach they expected to walk across.

The Japanese [music] took casualties on the beaches that their operational plan hadn’t accounted for. Landing barges that grounded on the reef short of the shore forced infantry to wade through chest-deep water [music] under aimed fire and several boats were hit before the ramps could drop. Sections of the 2/22nd firing from prepared positions along the treeline put rounds into packed landing craft at ranges under 200 m and the first wave at certain points stalled in the shallows.

Japanese after-action reports noted that Australian fire discipline on the northern beaches was significantly heavier than intelligence had estimated and that clearing individual positions required repeated flanking attempts because the defenders didn’t break under the initial pressure, but 14 to 1 doesn’t bend.

 Japanese units flanked the Australian positions from multiple axes using their numerical advantage to encircle and cut off pockets of resistance one by one. Positions that held for hours were eventually surrounded and the men inside them faced a choice between surrender and breaking out through jungle they hadn’t reconnoitered. Communications [music] between Australian units broke down in the first hours.

 Runners couldn’t cross ground the Japanese infantry already occupied and the radios were either destroyed or out of range. Each pocket of resistance fought its own separate engagement, cut off from the others and from any central [music] coordination. By the time the sun came up, the harbor, both airstrips, and the town of Rabaul itself were [music] in Japanese hands.

By mid-morning on the 23rd, Colonel John Scanlan, commanding Lark Force, gave the order to withdraw inland. The perimeter was broken in several sectors, the harbor was lost, and continued resistance in fixed positions meant annihilation for no tactical result. >> [music] >> Scanlon’s order directed the surviving unit south into the interior of New Britain toward the opposite coast.

 The order was necessarily vague. There was no extraction plan, no assembly point with supplies, and no guarantee that anything waited on the southern shore. The word was disperse, move south, and [music] survive. The order itself didn’t reach every unit. Pockets of Australians still fighting along the eastern ridgelines [music] never received it, and held their positions until they were overrun, or until [music] the absence of any other friendly fire told them the rest of the garrison had already gone.

Scanlon himself was captured by Japanese forces within days. He spent the rest of the war in prison camps, and survived, one of the few senior officers from Lark Force to make it through. The jungle interior of New Britain was equatorial rainforest at its most hostile. Triple canopy blocked sunlight at ground level.

 Tracks, where they existed, were cut by rivers running waist-deep in the rains, and ankle-deep in mud the rest [music] of the time. The distance from Rabaul to the nearest point on the southern coast was roughly 150 km in a straight line, but there were no straight lines in that interior. Ridgelines, river gorges, [music] and swamp forest detours that doubled and tripled the actual distance walked.

The men moving through it carried whatever they’d grabbed when the withdrawal order came, a rifle, a water bottle, maybe a tin of bully beef. Most had no maps of the interior. Medical supplies were functionally zero. Malaria hit within the first week. Dysentery followed close behind, spreading through groups drinking from whatever water source they stumbled across.

Men who were already wounded from the fighting deteriorated fast, and conditions where infection was a certainty, and treatment was a fantasy. Groups fragmented as they moved. Units that had withdrawn together splintered into smaller parties of 10, then five, then two or three men pushing through jungle they couldn’t navigate with confidence.

 The physically strongest moved ahead. The weakest fell behind. Wounded men who couldn’t walk were carried by their mates until the carriers themselves were too sick or exhausted to continue and then choices were made in the mud that the survivors didn’t discuss afterward. The jungle ate energy at a rate that couldn’t be sustained on empty stomachs and food ran out long before the coast came into sight.

 The NGVR men, the ones who knew the island, became guides for groups that would otherwise have walked in circles. Their knowledge of the interior tracks [music] and river crossings pulled parties through terrain that would have finished them without local experience. The local Papuan population became the margin between survival and [music] total loss.

 Indigenous villagers along the escape routes hid Australian stragglers, fed them from [music] gardens that had barely enough to sustain the villages themselves, and guided them along trails the Japanese hadn’t mapped. Some Australians [music] spent weeks sheltered in single villages, too sick to move, nursed back to walking condition by people who had every reason to stay out of the war and chose to help anyway.

>> [music] >> The risk to those villagers was real. Japanese patrols executed anyone caught assisting Allied soldiers and the patrols were active across the interior. The help came without negotiation and without any promise of repayment. Dozens of Australians who survived Rabaul owed their lives entirely to people whose names never appeared in any official report.

 The men who reached the southern coast of New Britain found no fleet waiting. Evacuation, when it came, arrived [music] in the form of small civilian boats, trading vessels, mission launches, anything with a hull and an engine that could make the crossing to the Australian mainland or to nearby Allied-held islands. The numbers who made it aboard were a fraction [music] of the force that had started the march south.

Exact figures were impossible to compile at the time because Lark Force had effectively ceased to exist as a coherent unit. Men trickled out of the jungle over a period of weeks and some didn’t emerge for months. A handful of soldiers and NGVR men stayed hidden on New Britain for the better part of a year, surviving on village food and local knowledge before rescue vessels eventually reached them.

 The fighting, the retreat, and the jungle crossing accounted for hundreds of Lark Force’s casualties. What happened to the men who didn’t make it into the jungle was worse. In the days following the invasion, Japanese forces rounded up Australian prisoners across the Rabaul area. Roughly 160 of these men were marched to the Tol Plantation, a coconut estate on the north coast of New Britain, in early February 1942.

 Their hands were tied behind their backs with wire [music] and cord. The prisoners were separated into groups and moved to the edges of the plantation groves, out of sight of each other. The Japanese used bayonets. The men were run through in batches, bound together so they couldn’t break apart. The process took hours.

 [music] It was carried out methodically, one group at a time, without urgency or disorder. A small number of men at the edges of the groups managed to tear free [music] and crawl into the undergrowth during the confusion of each round. These survivors, fewer than 10, hid in the plantation’s drainage ditches and surrounding scrub until the Japanese withdrew.

Their testimony, delivered months later when they reached Allied lines, was the sole source of information about what happened at Tol. Without those men, the event would have entered the historical record as nothing more than a list of names marked missing, presumed lost. The Tol Plantation wasn’t a breakdown in field discipline or a unit acting outside orders.

 The organization of the event, the systematic grouping, the binding, the sequential method, pointed to a process that had been decided in advance by officers [music] who understood what they were directing. When Australian forces returned to New Britain in 1945, burial details located the remains at Tol and confirmed the survivors’ accounts.

The physical evidence matched the testimony. A war crimes investigation followed, and a small number of Japanese officers were eventually tried and convicted. The sentences [music] were light. Several of the convicted officers served reduced terms and were released within years. The scale of accountability was thin against the scale of what happened on that plantation, and the families of the men who were lost at Tol said so publicly for decades afterward.

The Australians who survived both the invasion and the jungle were a minority of Lark Force. >> [music] >> A larger group, more than 800 military personnel, remained prisoners in Japanese hands on New Britain through the first half of 1942. In June and July of that year, these prisoners were loaded onto Japanese transport ships for transfer to detention camps elsewhere in the occupied Pacific.

One of those ships was the Montevideo Maru, a converted passenger cargo vessel pressed into service [music] as a prisoner transport. She sailed from Rabaul carrying 845 Australian military prisoners and 209 civilians, missionaries, colonial administrators, plantation [music] owners, and workers who had been trapped on New Britain when the invasion hit.

On the 1st of July, 1942, the USS Sturgeon, an American submarine patrolling the South China [music] Sea, detected the Montevideo Maru steaming without visible prisoner of war markings or Red Cross identification. The submarine’s crew had no way of knowing who was aboard. The torpedo struck the hull amidships.

 The Montevideo Maru listed and sank within minutes, too fast for any organized abandonment, too fast for the hatches to the prisoner holds to be opened. The men below deck [music] had no chance. The Japanese crew lost 18 of their own in the sinking. Every prisoner and civilian on board was lost. >> [music] >> 1,054 people in a single sinking.

 It was and remains [music] the largest maritime disaster in Australian history. The number exceeded the combined Australian casualties of many individual battles across [music] both World Wars. The Japanese government didn’t report the sinking to the International Red Cross. The prisoners had been loaded without notification to any neutral body onto an unmarked ship in a war zone where Allied submarines operated with standing orders to engage enemy transport.

The Australian government learned fragments of the story over the following months, pieced together from intelligence intercepts and Japanese records captured later in the war. When a reasonably complete picture emerged, the information was classified. The legal situation was ugly. An Allied submarine had fired the torpedo, [music] and no international framework existed to assign liability for prisoners transported unmarked through an active combat zone.

The easiest bureaucratic response was to close the file and say nothing. >> [music] >> The families of the men aboard the Montevideo Maru received form letters telling them their relatives were missing, presumed prisoners of war. That status held for years. Wives wrote to the army, parents wrote to the Red Cross, brothers wrote to their local members of parliament.

 The replies were uniform, no further information available, inquiries are ongoing. The inquiries produced nothing because the people conducting them already knew the answer and had been told it was secret. Wartime security was the initial reason. Details of submarine operations and patrol areas in the South China Sea were operationally sensitive.

After the war ended, the justification shifted to diplomatic considerations, then to administrative delay, then to silence by inertia. The result for the families was identical regardless of the reason. They waited and nobody told them anything. Some families didn’t receive confirmation of what had happened until the 1950s, nearly a decade after the war ended.

 Others worked it out themselves through contact with other families, through returned [music] prisoners who’d heard rumors in the camps, or through sheer persistence with archives that gave up information one reluctant page at a time. A number of families never received a definitive answer at all. The parents who’d sent their sons off to war passed away, still writing letters to departments that had stopped responding.

Questions were eventually raised in the Australian parliament, mostly by members whose electorates contained clusters of affected families. The answers from the government benches were exercises in deflection, expressions of sympathy followed by references to ongoing processes that had already concluded behind closed doors years earlier.

In 2009, the wreck of the Montevideo Maru was located on the seafloor off the coast of the Philippines by a private search expedition funded [music] largely by the families themselves. The discovery brought the story briefly into public view, but the remains of the men aboard stayed at the bottom of the South China Sea.

 The depth and condition [music] of the wreck made retrieval impractical, and the government offered no funding to try. For the families, finding the ship was the closest thing to a grave they would ever get. The Montevideo Maru sat outside Australian public [music] consciousness for decades. There was no national memorial until 2012, when a monument was finally erected in Canberra, 70 years after the sinking.

The dedication ceremony was attended by the children and grandchildren of the men who’d been lost, most of them elderly themselves by that point. The generation that had waited longest for acknowledgement [music] was largely gone before the acknowledgement arrived. Rabaul itself became the thing Australia had tried to prevent.

 Within months of the invasion, the Japanese turned it into the largest forward base in the Southwest Pacific. By 1943, the garrison exceeded 100,000 personnel. Engineers carved tunnels into the volcanic hills surrounding the harbor, creating a network of bunkers, supply depots, and command centers that was functionally immune to aerial bombing.

The harbor sheltered warships, submarines, and transport vessels, staging operations across New Guinea, the Solomon Islands, and the Bismarck Sea. The airstrips that Lark Force had guarded with training planes now launched Japanese bombers against Allied positions from Port Moresby to Guadalcanal. Allied command eventually decided that assaulting Rabaul directly would cost more than it was worth.

 The base was bypassed, surrounded, bombed, and left to wither. The Japanese garrison held out until the formal surrender in August 1945, by which point the 100,000 men inside the perimeter were starving, sick, and cut off from resupply. The strategic prize that had cost Lark Force everything sat out the end of the war in irrelevance, too strong to assault and too isolated to matter.

Of the 1,400 Australians who made up Lark Force when the first Japanese bomb fell on Rabaul, fewer than 400 survived the war. The rest were lost to combat on the beaches, to bayonets at the Tol Plantation, to disease and exhaustion in the jungle, or to a torpedo in the South China Sea fired by a submarine that was technically on their side.

The 2/22nd Battalion ceased to exist as a fighting unit on the 23rd of January 1942, less than 2 months after it had been deployed. Its personnel files became casualty lists, and its casualty lists became filing cabinet problems for clerks in Melbourne who processed the paperwork with stamps and signatures, and moved on to the next folder.

 The deployment order for Lark Force sits in the Australian War Memorial Archives. The language is flat, bureaucratic, and specific. There was no plan for reinforcement. There was no plan for withdrawal. The men were sent to hold a position that their own command assessed as indefensible for a duration that their own command defined as “until the enemy arrives.

” The people who wrote that order went home to their families in Canberra that evening. The men who received it dug foxholes in volcanic soil on the far side of New Britain, and watched the sky for bombers.