political center of East Asia, and traditionally, the states of East Asia had acknowledged the emperors of China as their overlords and paid tribute in exchange for being allowed to trade with China. Japan had usually resisted the demand to pay tribute to China, but shōgun Ashikaga Yoshimitsu had acknowledged the emperor of China as his overlord in return for access to the huge Chinese market. Japan's right to pay tribute and, with it, the right to trade with China was ended in the 1540s by the Ming court in response to raids by Sino-Japanese pirates known as the wakō. By seeking to invade China, Hideyoshi was in effect claiming for Japan the role traditionally played by China in East Asia as the center of the East Asian international order. He rallied support in Japan as a man of relatively humble origins who owed his position to his military might. Finally, during the 1540s–1550s, the wakō had staged a series of samurai raids into Korea, some of which were so large as to be "mini-invasions". Hideyoshi mistakenly thought his enemies were weak. Hideyoshi planned for a possible war with Korea long before he had completed the unification of Japan. He made preparations on many fronts. As early as 1578, Hideyoshi, then fighting under Oda Nobunaga against Mōri Terumoto for control of the Chūgoku region, informed Terumoto of Nobunaga's plan to invade China. In 1585, Hideyoshi told the Portuguese Jesuit Father Gaspar Coelho of his wish to conquer all of East Asia. Hideyoshi asked Coelho to send a message to his master, King Philip II of Spain, who was also King Philip I of Portugal, asking that he make his navy available to help Japan (Ming China, Spain, and Portugal were the main naval powers of the time). However Philip refused Hideyoshi, preferring not to upset China. The defeat of the Odawara-based Hōjō clan in 1590 finally brought about the second unification of Japan, and Hideyoshi began preparing for the next war. Beginning in March 1591, the Kyūshū daimyōs and their labor forces constructed Nagoya Castle in Nagoya, Saga (modern-day Karatsu, Saga, not to be confused with present day Nagoya city in Aichi Prefecture) as the center for the mobilization of the invasion forces. In 1592, Hideyoshi sent a letter to the Philippines demanding tribute from the Spanish governor general and stating that Japan had already received tribute from Korea (which