Tarakan Island
On 1 May 1945, Mackey's battalion, as part of 26th Brigade Group, landed at Lingkas Beach on Tarakan Island, off North Borneo. The island's airfield was to be captured to allow its use in operations against Borneo. Advancing inland along the Aman River, the battalion were held up by Japanese defending a stronghold known as Helen. On 12 May 1945, Mackey's company was to continue an attack that had begun three days previously and it was during this action that he earned the Victoria Cross (VC). The citation for his VC read: