The early years of 1336 to 1392 of the Muromachi period is also known as the Nanboku-chō or Northern and Southern Court period (南北朝時代 Nanbokuchō-jidai). The later years of 1467 to the end of the Muromachi period is also known as the Sengoku period.
Yoshimitsu allowed the constables, who had had limited powers during the Kamakura period, to become strong regional rulers, later called daimyo (大名). In time, a balance of power evolved between the shogun and the daimyo; the three most prominent daimyo families rotated as deputies to the shogun at Kyoto. Yoshimitsu was finally successful in reunifying the Northern Court and the Southern Court in 1392, but, despite his promise of greater balance between the imperial lines, the Northern Court maintained control over the throne thereafter. The line of shoguns gradually weakened after Yoshimitsu and increasingly lost power to the daimyo and other regional strongmen. The shogun's decisions about imperial succession became meaningless, and the daimyo backed their own candidates. In time, the Ashikaga family had its own succession problems, resulting finally in the Ōnin War (応仁の乱 Ōnin no Ran, 1467–1477), which left Kyoto devastated and effectively ended the national authority of the bakufu. The power vacuum that ensued launched a century of anarchy (see Provincial Wars and Foreign Contacts).
Contact with Ming Dynasty (明, 1368-1644) China was renewed during the Muromachi period after the Chinese sought support in suppressing Japanese pirates in coastal areas of China. Japanese pirates of this era and region were referred to as 倭寇, wokou, by the Chinese (Japanese wakō). Wanting to improve relations with China and to rid Japan of the wokou threat, Yoshimitsu accepted a relationship with the Chinese that was to last for half a century. In 1401 he restarted the tribute system, describing himself in a letter to the Chinese Emperor as "Your subject, the King of Japan". Japanese wood, sulphur, copper ore, swords, and folding fans were traded for Chinese silk, porcelain, books, and coins, in what the Chinese considered tribute but the Japanese saw as profitable trade.
During the time of the Ashikaga bakufu, a new national culture, called Muromachi culture, emerged from the bakufu headquarters in Kyoto to reach all levels of society. Zen (禅) Buddhism played a large role in spreading not only religious but also artistic influences, especially those derived from painting of the Chinese Song (960-1279), Yuan, and Ming dynasties. The proximity of the imperial court to the bakufu resulted in a commingling of imperial family members, courtiers, daimyo, samurai, and Zen priests. Art of all kinds—architecture, literature, Noh (能) drama, comedy, poetry, the tea ceremony, landscape gardening, and flower arranging—all flourished during Muromachi times.
There also was renewed interest in Shinto (神道), which had quietly coexisted with Buddhism (仏教 Bukkyo) during the centuries of the latter's predominance. In fact, Shinto, which lacked its own scriptures and had few prayers, had as a result of syncretic practices begun in the Nara period, widely adopted Shingon Buddhist rituals. Between the eighth and fourteenth centuries, Shintoism was nearly totally absorbed by Buddhism, becoming known as Ryōbu Shinto (Dual Shinto). The Mongol invasions in the late thirteenth century, however, evoked a national consciousness of the role of the kamikaze in defeating the enemy. Less than fifty years later (1339-43), Kitabatake Chikafusa (北畠 親房, 1293-1354), the chief commander of the Southern Court forces, wrote the Jinnōshōtōki (神皇正統記, 'Chronicle of the Direct Descent of the Divine Sovereigns'). This chronicle emphasized the importance of maintaining the divine descent of the imperial line from Amaterasu to the current emperor, a condition that gave Japan a special national polity (kokutai). Besides reinforcing the concept of the emperor as a deity, the Jinnōshōtōki provided a Shinto view of history, which stressed the divine nature of all Japanese and the country's spiritual supremacy over China and India. As a result, a change gradually occurred in the balance between the dual Buddhist–Shinto religious practice. Between the fourteenth and seventeenth centuries, Shinto reemerged as the primary belief system, developed its own philosophy and scripture (based on Confucian and Buddhist canons), and became a powerful nationalistic force.
By the end of the Muromachi period, the first Europeans had arrived. The Portuguese landed in southern Kyūshū (九州) in 1543 and within two years were making regular port calls, initiated the century-long Nanban trade period. The Spanish arrived in 1587, followed by the Dutch in 1609. The Japanese began to attempt studies of European civilization in depth, and new opportunities were presented for the economy, along with serious political challenges. European firearms, fabrics, glassware, clocks, tobacco, and other Western innovations were traded for Japanese gold and silver. Significant wealth was accumulated through trade, and lesser daimyo, especially in Kyūshū, greatly increased their power. Provincial wars became more deadly with the introduction of firearms, such as muskets and cannons, and greater use of infantry.
Christianity had an impact on Japan, largely through the efforts of the Jesuits, led first by Saint Francis Xavier (1506–1552), who arrived in Kagoshima in southern Kyūshū in 1549. Both daimyo and merchants seeking better trade arrangements as well as peasants were among the converts. By 1560 Kyoto had become another major area of missionary activity in Japan. In 1568 the port of Nagasaki, in northwestern Kyūshū, was established by a Christian daimyo and was turned over to Jesuit administration in 1579. By 1582 there were as many as 150,000 converts (two per cent of the population) and 200 churches. But bakufu tolerance for this alien influence diminished as the country became more unified and openness decreased. Proscriptions against Christianity began in 1587 and outright persecutions in 1597. Although foreign trade was still encouraged, it was closely regulated, and by 1640 the exclusion and suppression of Christianity had become national policy (see Tokugawa Period, 1600–1867, this ch.; Religious and Philosophical Traditions, ch. 2).