Zealand and the United Kingdom signed the Nauru Island Agreement in 1919, creating a board known as the British Phosphate Commission (BPC) that took over the rights to phosphate mining.
The island experienced an influenza epidemic in 1920, with a mortality rate of 18 per cent among native Nauruans. In 1923, the League of Nations gave Australia a trustee mandate over Nauru, with the United Kingdom and New Zealand as co-trustees. On 6 and 7 December 1940, the German auxiliary cruisers Komet and Orion sank five supply ships in the vicinity of Nauru. Komet then shelled Nauru's phosphate mining areas, oil storage depots, and the ship loading cantilever.
U.S. Army Air Force bombing the Japanese airstrip on Nauru
Japanese troops occupied Nauru on 25 August 1942. The Japanese built an airfield which was bombed for the first time on 25 March 1943, preventing food supplies from being flown to Nauru. The Japanese deported 1,200 Nauruans to work as labourers in the Chuuk islands. Nauru, which had been bypassed and left to "wither on the vine" by American forces, was finally liberated on 13 September 1945, when commander Hisayaki Soeda surrendered the island to the Australian Army and the Royal Australian Navy. This surrender was accepted by Brigadier J. R. Stevenson, who represented Lieutenant General Vernon Sturdee, the commander of the First Australian Army, on board the warship HMAS Diamantina. Arrangements were made to repatriate from Chuuk the 737 Nauruans who survived Japanese captivity there. They were returned to Nauru by the BPC ship Trienza in January 1946. In 1947, a trusteeship was established by the United Nations, with Australia, New Zealand, and the United Kingdom as trustees.
Nauru became self-governing in January 1966, and following a two-year constitutional convention it became independent in 1968 under founding president Hammer De Roburt. In 1967, the people of Nauru purchased the assets of the British Phosphate
