Before World War I, Japan had gained several substantial colonial possessions in East Asia such as Taiwan (1895) and Korea (1910). Japan joined the allies in World War I, and after the war acquired the South Seas Mandate, the former German colony in Micronesia, as a League of Nations Mandate. Pursuing a colonial policy comparable to those of European powers, Japan settled significant populations of ethnic Japanese in its colonies while simultaneously suppressing Indigenous ethnic populations by enforcing the learning and use of the Japanese language in schools. Other methods such as public interaction, and attempts to eradicate the use of Korean, Hokkien, and Hakka among the Indigenous peoples, were seen to be used. Japan also set up the Imperial Universities in Korea (Keijō Imperial University) and Taiwan (Taihoku Imperial University) to compel education.