British traders became regular visitors to Palau in the 18th century, followed by expanding Spanish influence in the 19th century. Palau, under the name "Palaos", was included in the Malolos Congress in 1898, the first revolutionary congress in the Philippines, which wanted full independence from colonialists. Palau, at the time, was part of the Spanish East Indies headquartered in the Philippines. Palau had one appointed member to the Congress, becoming the only group of islands in the entire Caroline Islands granted high representation in a non-colonial Philippine Congress. The Congress also supported the right of Palau to self-determination if ever it wished to pursue such a path. Later in 1899 as part of the Caroline Islands, Palau was sold by the Spanish Empire to the German Empire as part of German New Guinea in the German–Spanish Treaty (1899). During World War I, the Japanese Empire annexed the islands after seizing them from Germany in 1914. Following World War I, the League of Nations formally placed the islands under Japanese administration as part of the South Seas Mandate. In World War II, Palau was used by Japan to support its 1941 invasion of the Philippines, which succeeded in 1942. The invasion overthrew the American-installed Commonwealth government in the Philippines and installed the Japanese-backed Second Philippine Republic in 1943.