In Sixteenth-Century Japan, civil war that marked the last years of Ashikaga shogunate saw the emergence of three successive brilliant military leaders: Oda Nobunaga, Toyotomi Hideyoshi, and Tokugawa Ieyasu. The Tokugawa shogunate ruled Japan from Edo until 1869 and imposed strong central control over all of Japan for the first time. During the years of civil war, Portuguese ships had frequented Japanese ports, bringing European weapons and Catholic missionaries to islands. Many Japanese were converted to Christianity, and European guns played a key role in the warfare. Under strict Tokugawa control, Japan enjoyed over two centuries of order, prosperity, and economic growth. Japan had retained Confucianism especially within aristocratic class, and it was revived and strengthened under Tokugawa rule as suiting admirably their feudal and hierarchical system and their stress on loyalty. The combination of missionaries and traders as agents of foreign influence or even colonial expansion was disturbing to smooth order the Tokugawa had worked so hard to establish.