Mōri Family, a clan that dominated the strategic western Honshu region of south-central Japan from early in the 16th century to the middle of the 19th century.
After the Tokugawa family had reconstituted Japan’s central government in 1603, the head of the Mōri family became the daimyo, or feudal lord, of Chōshū, the han (fief) that encompassed most of the western Honshu region. Although the Tokugawa tolerated the existence of the Mōri in Chōshū, the two clans remained hostile toward each other. Chōshū warriors played the leading role in the overthrow of the Tokugawa government in 1867, after which Chōshū men dominated the new government until the end of World War II.
The Mōri family first achieved prominence in the early 16th century when some vassals of the Ōuchi family, then the dominant power in west Honshu and probably the most powerful warriors in all Japan, revolted against the Ōuchi’s autocratic rule. Under the leadership of Mōri Motonari (1497–1571), his family, though not directly involved in the uprising, was able to profit by the revolt, and in 1557 he became the new overlord of west Honshu.
Motonari’s grandson, Mōri Terumoto (1553–1625), became the major opponent of Oda Nobunaga when that great warrior made his bid to reunify Japan. After Oda was assassinated in 1582 Terumoto made peace with Oda’s successor, Toyotomi Hideyoshi, whose trusted general he became. Before Hideyoshi died in 1598, he named Terumoto as one of the five regents who were to govern the country for his infant son, Hideyori. When fighting erupted among the regents, Terumoto sided against Tokugawa Ieyasu, the eventual victor. Because Terumoto’s resistance had been minimal, the Mōri family was permitted to retain almost half of its Chōshū domain.
Nevertheless, throughout the Tokugawa period (1603–1867) the Mōri family indoctrinated their warriors with hatred of the Tokugawa family and respect for the emperor, whose power the Tokugawa usurped. When Chōshū warriors led the fight to overthrow the Tokugawa in 1867, they did so under the banner of restoring power to the emperor.