 Complete the following phrase:  The Ryūkyū Islands are composed of more than 140 islands, 40 of which inhabited, that lie beneath the southernmost Japanese main islands. A point of contention throughout the years, ownership of Ryūkyū was often disputed by major powers. The island of Okinawa was first ruled by warlords, called either aji or anji, and was unified under the rule of Shō Hashi in the early fifteenth century Smits 90. Eventually Okinawa conquered the rest of the Ryūkyū Islands, expanding its small kingdom. Trade was booming in East Asia in the late fifteenth and early sixteenth centuries and Ryūkyūs position as a middleman helped foster relationships with Japan and China. Once trade diminished, Ryūkyū faced the threat of invasion by Japan. In 1609, the Satsuma domain 