In July 1842, James Brooke's ship, the
Royalist, anchored off PMB, a low, sandy island near the mouth of the Brunei River. Known for its abundance of
wild boars and excellent fishing. Situated along the northwestern coast, the island acted as a natural bridge between the striking coastal landscapes north of Brunei Town (now
Bandar Seri Begawan) and the more subdued lowland shores to the south. Brooke anchored off PMB in July 1846 with the help of Sir
Thomas John Cochrane and the Royal Navy. From this vantage point, Brooke could keep an eye on events in Brunei, where
Sultan Omar Ali Saifuddin II's agents were trying to create dissatisfaction in Brooke's territory. Brooke appreciated England's support even if at first he intended to act on his own initiative. Given the intricate political landscape, Cochrane chose not to become involved in Brunei's domestic affairs directly. However, the navy demonstrated England's presence and willingness to uphold regional stability by anchoring off the island. PMB was strategically significant during the Second World War, particularly in Operation Oboe 6 in June 1945, when Australian forces attacked Japanese positions in Brunei. As part of the broader campaign to liberate Borneo, the Australians targeted key coastal defences on PMB, which included anti-aircraft positions near Cape Sapo and Brooketon overlooking Yellow Beach. Although the Japanese fortifications here were not as formidable as those on
Tarakan, they still posed a threat to amphibious landings, with artillery and anti-aircraft guns positioned to disrupt an assault. The Japanese garrison, despite being understrength and poorly supplied, could still inflict heavy casualties if they chose to fight to the last man. At Cape Sapo, on the island’s southern tip, the occupiers had constructed five piers, about 300 metres in total length in waters 10 metres deep, to allow amphibious supply ships to dock during their occupation of Brunei. As part of a coordinated divisional effort, the
20th Brigade, under the command of Brigadier
Victor Windeyer, was tasked with securing PMB during Operation Oboe 6. The brigade was to attack both
Green Beach on the Bruneian peninsula and White Beach on PMB simultaneously, with Yellow Beach becoming operational once the island was secured. To clear the southern channel around the island and provide access to Yellow Beach, the
2/15th Battalion was assigned the mission of landing at White Beach and then moving southwest to capture Cape Sapo and Red Beach. Prior to the PMB landing during Oboe 6, pre-landing air operations were conducted in two phases. From 3 May to 7 June, US and Australian bombers targeted Japanese military positions in Brunei Bay and other areas. In the second phase, from 7 June to Z Day, the focus shifted to supporting minesweeping operations, convoy protection, and targeting specific enemy positions, including those on PMB. On 9–10 June, bombings were carried out over mainland Brunei, PMB, and
Labuan Island every two hours. Additionally, naval
minesweeping operations cleared a channel into Brunei Bay, while the Cruiser Covering Group conducted bombardments to mark the approach to White Beach. landing on the island in 1945 Following intense air and naval bombardment, the 2/15th Battalion successfully landed at White Beach. While an initial disorganization due to a trailing right flank caused some confusion, the subsequent waves landed without incident. There was no enemy defence of the shore, and by 17:45, the battalion had secured the island with no opposition. The beachhead was established, and Yellow Beach was opened for logistical support after engineers cleared rubble from the beach, causing a slight delay in the unloading of supplies. The successful seizure of PMB enabled operations in the area to continue. On 19 June, men from the 2/15th Battalion departed from Yellow Beach, heading to the
LSTs off PMB. The played a vital role in supporting operations around PMB. In June 1945, the ship operated in Brunei Bay with a key anchorage at PMB, participating in missions around Brunei Bay. The ship provided essential support to Australian forces during Oboe 6. From July 1945 until the end of the war, the ship was stationed at the island. On 15 August 1945, when Japan accepted the terms of the
Potsdam Declaration and offensive operations came to an end, the ship stayed at PMB until September. During this time, the ship tended to
PT boats and supported
Australian occupation forces in North Borneo. It also conducted several missions, including transporting troops and supplies, before returning to Brunei Bay in late September. In 1967, a temporary site at PMB was selected to serve as the Government Marine Base, with the suggestion to establish a veterinary quarantine station on the island. Since 1980, and continuing through its recent developments, various areas of the island have been utilised for training by the
Royal Brunei Armed Forces. == Economy ==