十五・十六世紀大友氏の対外交渉

抄録

The Otomo family (大友氏), which dominated a large part of northern Kyushu (九州) had a firm intention to trade in Southeast Asia. The Muromachi shogunate (室町幕府) ordered them to remit sulfur for export. Then Otomo Ujitoki managed two sulfur mines in the mountain district of Bungo (豊後). Otomo Chikayo expanded the mining business geographically, and built a big ship called the "Kasuga-maru (春日丸)". The Otomos dispatched trade ships to Korea, China, the Ryukyus (琉球), and several countries of Southeast Asia. In particular, Otomo Yoshishige and Ouchi Yoshinaga, who were brothers, dispatched a fleet to China for trade, but they were considered as smugglers by the government. They went to the coastal areas of the South China Sea, and traded with the merchants who passed through there.