A striking incident occurred in 1419, when a flotilla of thirteen hundred ships of war from Mongolia, Korea, and Namban (the countries south of China) appeared off Tsushima. The Kiushū barons, headed by the Sō and the Shibukawa families, who held the office of governors of Kiushū, beat off the invaders and slaughtered an immense number of them. Thenceforth Korea held Japan in awe and made no attempts against her. In 1440 the Korean government established amicable relations with the Sō family, sent presents of valuable books and opened commercial intercourse. The same year another Chinese envoy arrived with dispatches demanding in a peremptory tone the establishment of amity between the two empires, but the Shōgun Yoshimochi declined to entertain the proposal. In the time of the Shōgun Yoshinori, however, official intercourse with China was reopened, the emperor sending to Japan two hundred tickets in the nature of passports which were placed by the shōgunate in the charge of the Ōuchi family. The Sō family was then appointed to control the trade with Korea, that with China being intrusted to Ōuchi. Under the Shōgun Yoshimasa intercourse with China received considerable development, and parcels of books as well as quantities of copper coin were frequently forwarded to Japan at her request. The Ming sovereigns always complied with Japan's wishes in these matters, but considerable irregularities occurred in the trade between the two nations, owing to selfish disregard of the regulations issued for its control. Moreover, Japanese from Kiushū and other places crossed over to China, carrying with them not only legitimate articles of trade, but also implements of war. They pretended that the latter were gifts from the Japanese government to China, but they did not hesitate to use them for purposes of intimidation when they found an opportunity to plunder the Chinese.