The battle took place between 22 April and 6 June 1944 and formed part of the New Guinea campaign. The operation consisted of two landings, one at Tanahmerah Bay and the other at Humboldt Bay, near Hollandia. The landings were undertaken simultaneously with the amphibious invasion of Aitape ("Operation Persecution") to the east. The battle was an unqualified success for the Allied forces, resulting in a withdrawal by the Japanese to a new strategic defense line in the west of New Guinea and the abandonment of all positions in the east of the island.