The Japanese invasion of Borneo

At dawn on 16 December 1941 Japanese landing barges came ashore on the beaches near Miri in Sarawak and near Seria in neighbouring Brunei, on the north-west coast of Borneo. Major General Kiyotake Kawaguchi’s troops were to seize the only oilfields in the British part of the island, and then the airfields from which Singapore, Sumatra and Java could be reached. They took them almost without a fight, but found ruins: for a week the British had been destroying the wells, the pipelines and the refinery. A week later, on 23 December, a Japanese convoy entered the mouth of the Santubong River near Kuching, the capital of Sarawak. Despite losses inflicted by Dutch submarines, the Japanese entered the city on Christmas Eve, and on 25 December they captured its airfield after fierce fighting against the only battalion of regular infantry the British had on the entire island. This was the first link in Japan’s march on the oil of the Dutch East Indies, for the sake of which Tokyo had decided to go to war at all.

A divided island rich in oil

In 1941 Borneo, the third-largest island in the world, was divided between two empires. The larger southern and central part belonged to the Dutch East Indies. The north was shared among several territories under British protection. The largest was Sarawak, for a hundred years a peculiar state ruled by an English family, the Brookes – the so-called White Rajahs. The first of them, James Brooke, had received the land from the Sultan of Brunei in 1841, and from 1888 the Kingdom of Sarawak was a British protectorate. The third Rajah, Charles Vyner Brooke, marked the centenary of the dynasty’s rule in September 1941 by granting the country a constitution that limited his own power. When the Pacific war broke out he was in Australia, and he did not return to Sarawak during the war. Alongside lay the small Sultanate of Brunei, also a British protectorate, the island of Labuan, part of the Straits Settlements colony, and North Borneo, administered by a British chartered company.

What gave this corner of the world its importance was oil. It had been extracted at Miri since 1910, and in the 1930s a field was opened at Seria, just across the Brunei border, which quickly outgrew Miri’s and, according to some figures, was producing around 17,000 barrels a day before the war. Both fields and the refinery at Lutong were worked by companies of the Shell group. Even richer deposits lay in the Dutch part of the island: on the island of Tarakan off the east coast and around Balikpapan, where there was a large refinery.

It was this oil that Japan reached for. Since July 1941 – when, after the occupation of southern Indochina, the United States froze Japanese assets and then halted oil deliveries, and the Dutch in Batavia suspended their own supplies – the Imperial Navy and Japanese industry had been living off dwindling stocks. The war plan approved in Tokyo that autumn provided for the army to occupy Malaya, the Philippines and British Borneo in the first weeks of the war and then, in a second stage, the oil-bearing Dutch islands. British Borneo was to be taken by the army, the Dutch part mainly by the navy.

A defence that did not exist

The British knew that Borneo was defenceless. The island had no roads or railways that would allow troops to be moved, and there were not enough men, aircraft or ships to defend it. The command in Singapore, and later General Arthur Percival, commanding in Malaya, therefore set a modest goal: to destroy the oil installations before they fell into enemy hands and to delay the capture of the airfield near Kuching for as long as possible. For this task they sent the 2nd Battalion of the 15th Punjab Regiment of the British Indian Army, which arrived in Sarawak between December 1940 and May 1941. Together with a small artillery battery, sappers, local volunteers, the police and a coastal guard, it formed the so-called Sarawak Force (SARFOR) under the battalion’s commander, Lieutenant Colonel C.M. Lane. The battalion itself numbered about a thousand men; the whole force, including the local units drawn largely from the Iban and other Dayak peoples, numbered about two and a half thousand according to some accounts. North Borneo, Brunei and Labuan were left practically without troops.

Preparations for destroying the oil began long before the war. According to Percival’s account, the plans were drawn up in August 1941. Surplus equipment was shipped out, the Miri field was closed, some of the wells at Seria were sealed with concrete, and one of the units of the Lutong refinery was shut down. When news of the Japanese landing in Malaya arrived on 8 December, the sappers began the final demolitions: they blew up machinery, set tanks on fire and plugged the wells. On 13 December the Punjabi detachment from Miri sailed for Kuching. In the north of the island no one was left who could offer resistance.

The landings at Miri and Seria

The Japanese invasion force, known after its commander as the Kawaguchi Detachment, was built around the headquarters of the 35th Infantry Brigade and the 124th Infantry Regiment of the 18th Division, which had previously fought in southern China, around Canton. They were accompanied by men of the Yokosuka 2nd Special Naval Landing Force – Japanese naval infantry – and a group of about 150 oil specialists who were to get the wells working again as quickly as possible. On 13 December ten transports left Cam Ranh Bay in Japanese-occupied Indochina. They were escorted by Rear Admiral Shintarō Hashimoto’s light cruiser Yura and four destroyers, with distant cover provided by Rear Admiral Takeo Kurita’s force with the heavy cruisers Kumano and Suzuya.

The convoy reached its destination undetected. Unloading began on the night of 15–16 December, hampered by a heavy swell that overturned barges and cost the Japanese their first casualties. By dawn two groups were already ashore, near Miri and near Seria. That same day the Japanese occupied Kuala Belait and the refinery at Lutong. Sources give very different figures for the number of troops landed, from a few thousand to around ten thousand. There was almost no resistance, because there was no one to offer it. The victory, however, proved only partial. The wells were plugged or destroyed, the refinery wrecked, and the Japanese specialists needed many months to restore even part of the production.

The Dutch response

Although Japan was not yet formally at war with the Netherlands and wanted the Dutch to remain passive, the Dutch had themselves declared a state of war with Japan on 8 December, and from the first day of the invasion of Borneo they fought alongside the British. On 17 December Martin B-10 bombers took off for Miri from the Singkawang II airfield in Dutch West Borneo, but missed their target. They were followed by three Dornier Do 24 flying boats of the Dutch naval air service. One was shot down, but another hit the destroyer Shinonome with two bombs, and she blew up and sank with all hands. Some researchers allow that the ship may have struck a mine, and the wreck has never been found. Further raids on 18 and 19 December delayed the next Japanese moves but could not stop them. The Japanese air force responded with attacks on the Singkawang II airfield, from which the Dutch began withdrawing their aircraft.

Kuching on Christmas Eve

On 22 December the greater part of the Kawaguchi Detachment re-embarked at Miri and sailed west towards Kuching. One battalion stayed behind in the oilfields; according to some sources the Japanese entered the town of Brunei that same day, according to others not until 1 January. On the way the convoy was spotted by a Dutch flying boat, which alerted the submarines. The Japanese nevertheless managed to enter the mouth of the Santubong on 23 December and began unloading that evening. It was then that the Dutch submarine K XIV, commanded by Lieutenant Commander Carel van Groeneveld, struck. On the evening of 23 December her torpedoes sank the transports Hiyoshi Maru and Katori Maru and damaged two others; the badly hit Hokkai Maru had to be beached. Several hundred Japanese soldiers were killed. On 24 December a second Dutch submarine, K XVI, torpedoed the destroyer Sagiri about 35 nautical miles from Kuching; after her magazine exploded she sank, taking 121 members of her crew with her. She is often described as the first Japanese warship sunk by an Allied submarine. The next day K XVI herself fell victim to the Japanese submarine I-66 and went down with all hands.

On land the Japanese moved fast. On the morning of 24 December Colonel Akinosuke Oka’s detachment landed near Cape Sipang and pushed inland, and on Christmas Eve itself the Japanese entered Kuching, which the authorities and the troops had abandoned. Some accounts date the capture of the city to 26 December, but most give 24 December. Lieutenant Colonel Lane, in accordance with orders from Singapore, concentrated his forces around the airfield a dozen or so kilometres from the city. Its runway had already been destroyed by the sappers, but the defenders were to buy time. During the night of 24–25 December and throughout the following day the Punjabis beat off attacks by Japanese infantry. They were, however, threatened with encirclement, and at about 4.40 p.m. on 25 December the Japanese took the airfield. Some companies failed to withdraw in time and were destroyed or captured. Sources differ on the number of dead on both sides. The remaining Punjabis made their way through the jungle to the Dutch side of the border, where, together with soldiers of the Royal Netherlands East Indies Army (KNIL), they were to defend the Singkawang II airfield.

For the first time in a hundred years the people of Kuching found themselves under a power that was not the Brooke government. European officials were interned. Many of them, like the soldiers later, were held in the Batu Lintang camp near Kuching, set up in barracks built before the war for the Punjabi battalion.

Paratroopers over Sumatra? A dispute over the date

Many chronologies carry, under 28 December 1941, a report of Japanese paratroopers landing on Sumatra. This is a mistake. Japanese army paratroopers, a regiment of the Teishin Shudan airborne group, landed near Palembang in southern Sumatra only on 14 February 1942, to seize the refineries and airfield there while Singapore was in its death throes. In the last days of December 1941 Sumatra was still an Allied rear area. On 27 December the British decided to move their bomber bases there from threatened Singapore and began preparing two airfields near Palembang, one of them hidden in the jungle, which the Japanese long knew nothing about. Yet the war reached the island too: according to the loss records of the Dutch airline KNILM, on 28 December Japanese fighters strafed the airfield at Medan in northern Sumatra and destroyed a Douglas DC-3 airliner on the ground. That same day Dutch bombers, now operating from Singapore, once again attacked the Japanese at Kuching.

Place in the war

The capture of Miri, Seria and Kuching was a small campaign on the margins of the war for Malaya, where in those same days the Japanese sank the Prince of Wales and the Repulse and pressed south down the peninsula. Yet it showed what the coming months would look like. The Japanese acted quickly, with economical forces and according to plan, while the Allies defended themselves dispersed, without air power or a fleet, hoping at best to destroy what they could not hold. The Punjabis and the Dutch fought on in the jungle of western Borneo until the end of January 1942, when the Japanese took the last airfield in that part of the island, and the remnants of the battalion did not surrender until the spring. In the first weeks of January the Kawaguchi Detachment occupied Labuan and Jesselton (today Kota Kinabalu), and on 19 January the Governor of North Borneo surrendered Sandakan. The whole of British Borneo was in Japanese hands.

At the same time the navy struck at the Dutch part of the island. On 11 January 1942 the Japanese landed on Tarakan, and on 24 January near Balikpapan. In both places Dutch sappers managed to set the wells and refineries on fire. On Tarakan the Japanese murdered the captured gunners of a coastal battery that had fired on their minesweepers after the island’s surrender, and at Balikpapan, according to post-war findings, they killed a group of European prisoners and civilians in reprisal for the destruction of the oil installations. Even so, oil from Borneo and from Sumatra, taken in February, was soon flowing to Japan and fuelled its fleet for years to come. British Borneo remained under occupation for three and a half years, and its inhabitants and the prisoners of war paid a heavy price for it, the best-known symbol of which later became the death marches of prisoners from the Sandakan camp. The island was liberated in 1945, mainly by the Australians. Rajah Vyner Brooke returned to Kuching in April 1946 only to cede Sarawak to the British Crown on 1 July. The state of the White Rajahs did not survive the war, which for it had begun on 16 December 1941 on the beaches near Miri.