Tinian is one of the three principal islands of the Commonwealth of the Northern Marianas Islands. Tinian is about 5 miles (8km) southwest of its sister island, Saipan. It has a land area of about 40 sq.mi. (100 km²). Lightly populated, but heavily garrisoned by Japanese forces in World War II, Tinian, with its sister islands, had passed through Spanish and German hands prior to becoming a Protectorate of Japan after World War I. Under Japanese administration, Tinian was largely a sugar plantation.