During World War II, first the Allies and later the Japanese occupied Dili, and the mountainous interior of the colony became the scene of a guerrilla campaign, known as the Battle of Timor. Waged by East Timorese volunteers and Allied forces against the Japanese, the struggle resulted in the deaths of between 40,000 and 70,000 East Timorese civilians. The Japanese eventually drove the last of the Australian and Allied forces out. However, Portuguese control was reinstated after the Japanese surrender at the end of World War II.