Ieyasu (Ieyasu Tokugawa)ēāˈyäsō tōkōgäˈwə, 1542–1616, Japanese warrior and dictator. A gifted leader and brilliant general, he founded the Tokugawa shogunate. Early in his career he helped Nobunaga and Hideyoshi unify Japan. In 1590 he received the area surrounding Edo (Tokyo) in fief, and he later made Edo his capital. After Hideyoshi's death (1598), he became the most powerful daimyo by defeating rival barons in the battle of Sekigahara (1600). He became shogun in 1603, made his son Hidetada nominal ruler in 1605, subdued Hideyoshi's heirs in 1615, and at his death in 1616 was the undisputed dictator of Japan. He sought to perpetuate the supremacy of his family by freezing the status quo. Under his regime attendance at the shogunal court was compulsory, castle building was strictly controlled, and Confucianism was revived to strengthen the state. Like Hideyoshi, he encouraged foreign trade; Japanese vessels carried goods to China, the Philippines, and Mexico. Christians were at first tolerated because he wished to trade with Europe. After Ieyasu's death a great mausoleum was erected in his honor at Nikko, which became one of the most important shrines in Japan. His name also appears as Iyeyasu.