Tarakan is a small island off the north-eastern coast of Borneo. Prior to the Second World War it was part of the Dutch East Indies and an important oil-producing centre. In early 1942 it was occupied by the Japanese. Three years later, the recapture of Tarakan was to be the first in a series of operations in and around Borneo codenamed OBOE. Tarakan's significance lay in its oil infrastructure and in its airfield, which was to be used to support the other OBOE as part of a general advance towards Java. The operation was entrusted to brigade group based on the 9th Division's 26th Brigade which went ashore on the morning of 1 May. The landing was affected with little real difficulty but initiated a bitter campaign against Tarakan's Japanese defenders who had withdrawn inland. The fighting continued until the end of the war in August, by which time neither the island’s airfield or oil facilities had been returned to an operational condition.
The OBOE series of operations were some of the most controversial fought by Australian troops during the war. Many senior Australian officers considered them strategically unsound and felt they contributed little to the defeat of Japan. For sound political and military reasons of its own, however, the United States was reluctant to use Australian troops to re-conquer the Philippines. General Douglas MacArthur, the American theatre commander, was under considerable pressure from the Australian government to employ Australian troops in visible and meaningful roles.
225 Australians were killed as a result of Tarakan campaign. Relative to the number of troops involved, it was the most costly of all the OBOE operations. The entire 7th Division was employed at Balikpapan and it suffered only two more fatal casualties. Over 1,500 of the island's Japanese defenders were also killed.