The South Seas Mandate, officially the Mandate for the German Possessions in the Pacific Ocean Lying North of the Equator, was a League of Nations mandate in the "South Seas" given to the Empire of Japan by the League of Nations following World War I. The mandate consisted of islands in the north Pacific Ocean that had been part of German New Guinea within the German colonial empire until they were occupied by Japan during World War I. Japan governed the islands under the mandate as part of the Japanese colonial empire until World War II, when the United States captured the islands. The islands then became the United Nations–established Trust Territory of the Pacific Islands governed by the United States. The islands are now part of Palau, the Northern Mariana Islands, the Federated States of Micronesia, and the Marshall Islands. In Japan, the territory is known as and was governed by the . Origin Japanese interest in what it called the began in the 19th century, prior to its imperial expansion into Korea and China. By 1875, ships from the newly established Imperial Japanese Navy (IJN) began to hold training missions in the area. Shiga Shigetake, a writer who accompanied a Navy cruise to the region in 1886, published his in 1887, marking the first time a Japanese civilian published a firsthand account of Micronesia. Three years later, Shiga advocated for annexation of the area by claiming that doing so would "excite an expeditionary spirit in the demoralized Japanese race." Despite the appeal imperialism had for the Japanese public at the time, neither the Meiji government nor the Navy seized any pretexts to fulfill this popular aspiration. It was through the commercial operations of fisherman and traders that the Japanese first began to make a wider presence in the region, which continued to grow despite challenges from competing German commercial interests. Although the Japanese public's enthusiasm for southward expansion had abated by the turn of the century, a number of important intellectuals, businessmen, and military officials continued to advocate for it. Among them were Admiral Satō Tetsutarō and Diet member Takekoshi Yosaburō. The latter declared that the future of Japan "lies not in the north, but in the south, not on the continent, but on the ocean" and that its "great task" was to "turn the Pacific into a Japanese lake." By the outbreak of World War I the