Colonial period and aftermath
In 1910 the German colonial government during the administration of Governor Albert Hahl moved offices, the district court, a hospital and customs and postal facilities from Herbertsh�he (today�s Kokopo) to Simpsonhafen. That settlement was thus substantially enlarged with official buildings and housing and renamed Rabaul, meaning mangrove in Kuanua (the local language) as the new town was partially built on a reclaimed mangrove swamp.
At the outset of World War I, at the behest of Great Britain, Australia occupied German New Guinea with the volunteer Australian Naval and Military Expeditionary Force. Following Germany's defeat at the end of the war, the occupied territory was delegated in 1920 to Australia as a League of Nations Mandate (Class C). Rabaul became the capital of the Territory of New Guinea. Visits to and stays in Rabaul during this period were amply described in books by many authors, including Margaret Mead.
1937 eruption
Under the Australian administration, Rabaul developed into a regional base. Then in 1937, catastrophic volcanic eruptions destroyed the town after the two volcanoes, Tavurvur and Vulcan, exploded. 507 people were killed, and there was widespread damage.
Following this, the Australian administration for the Territory of New Guinea decided to move the territorial headquarters to the safer location of Lae. All long-term steps to re-establish the territorial headquarters at Rabaul were forestalled during World War II.
World War II
By the time the Japanese attacked Pearl Harbor it was apparent they would soon attack Rabaul. So, by December 1941, women and children (except for Chinese and the local indigenous) were evacuated. In January 1942 Rabaul was heavily bombed, and on 23 January the Battle of Rabaul began with the landing of thousands of Japanese naval landing forces.
During their occupation the Japanese developed Rabaul into
