Little is known of Nauruan prehistory except what is suggested by myth and legend. Tradition holds that Nauru was settled by Tabuarik, who came from Kiribati—as did subsequent boatloads of Kiribati people—and took over the island from a small group living there. In more recent times the Island was visited by whalers and escaped convicts from Norfolk Island and Australia. In 1886, an Anglo-German declaration assigned Nauru to Germany, who administered the island until 1914; after World War I the island became a League of Nations mandate under Australian administration. Following World War II, when the Japanese occupied the Island, Nauru was a United Nations trusteeship administered by Australia until 1968 when it became an independent republic. Its economic history is based on the discovery of phosphate in 1899, the mining of which commenced in 1906. Beginning in 1919 the British Phosphate Commissioners (BPC) administered the mining operation and took proportionate shares in the phosphate mined. The BPC initially paid those Nauruans whose land was mined a royalty of one half-penny per ton of phosphate shipped. Inadequate returns to Nauruans for their phosphate has been a contentious issue for which Nauruan leaders have sought redress. Since independence the Nauru Phosphate Corporation has sold the phosphate on the open market for high returns, and Nauru has taken a positive lead in Pacific island affaire, choosing to share some of its wealth through airline and shipping links with countries that have limited communication networks.