The German–Spanish Treaty of 1899, (; ) signed by the German Empire and the Kingdom of Spain, involved Spain selling the majority of its Pacific possessions not lost in the Spanish–American War to Germany for 25 million pesetas (equivalent to 17 million Marks). History During the 19th century, the Spanish Empire lost most of its colonies to independence movements. Then came the Spanish–American War in 1898, in which Spain lost most of its remaining colonies. Cuba became independent while the United States took possession of Puerto Rico along with the Philippines and Guam from Spain's Pacific Ocean colonies, the Spanish East Indies. This left Spain with only its African possessions of Spanish Sahara, Ifni, and Spanish Guinea, and with about 6,000 tiny, sparsely populated, and not very productive Pacific islands. The latter were both ungovernable, after the loss of the administrative center of Manila, and indefensible, after the destruction of two Spanish fleets in the Spanish–American War. The Spanish government, therefore, decided to sell the remaining islands. Germany lobbied the Spanish government to facilitate the sale of the islands to Germany. The Spanish Prime Minister Francisco Silvela signed the treaty on 12 February 1899. It transferred the Caroline Islands and the Northern Mariana Islands to Germany, which then placed them under the jurisdiction of German New Guinea. Palau, at the time considered part of the Carolines, was also occupied and during the following years the Germans started up mining there. The United States might have retained both the Carolines and Northern Marianas, but a lack of diplomatic consistency and interest allowed Spain to retain control until the sale. In October 1914, during World War I, the Empire of Japan invaded and conquered many of these German possessions. After the war, they became in 1919 the South Seas Mandate of the League of Nations, under control of the Japanese. During and after World War II the United States took control of the former Spanish and German archipelagos in the Pacific. Residual Spanish claims It has been asserted that some islands (Kapingamarangi, Nukuoro, Mapia, Rongrik, Ulithi, and "Matador", probably a reef already sunken today, but it appeared on maps of the time) are still in Spanish possession since they were not transferred to the United States nor to Germany. The hypothesis appeared on 5 March 1948, when the state lawyer and CSIC researcher Emilio Pastor y Santos wrote a letter claiming that