One of the most significant figures in Japanese history, Ieyasu was a warrior, statesman and founder of the Tokugawa dynasty of shoguns. Tokugawa Ieyasu was born Matsudaira Takechiyo in 1542, son of the lord of the province of Mikawa. At the time of his birth, Japan was convulsed by civil war, with violent feuds between territorial lords which had lasted for nearly a century. When he was four Ieyasu was sent as a hostage to secure an alliance between his clan and the neighbouring Imagawa clan. He was raised at their court and given the education suitable for a nobleman. In 1567 Ieyasu, whose father's death had left him as leader of the Matsudaira, allied with Oda Nobunaga, a powerful neighbour. It was at this time that he changed his name from Matsudaira to Tokugawa, which was the name of the area from which his family originated. He also changed his personal name to Ieyasu, so he was now known as Tokugawa Ieyasu. Ieyasu spent the next decade-and-a-half campaigning with Nobunaga while expanding his own influence and wealth. He had by now gained a considerable military reputation.
When Nobunaga was assassinated in 1582, Tokugawa Ieyasu acquired more territory, and allied with Nobunaga's successor, Toyotomi Hideyoshi. Hideyoshi sent Ieyasu to govern lands in the east of Japan, attempting to contain his growing independence. Ieyasu made his headquarters at the small port of Edo (where Tokyo now stands). When Hideyoshi died campaigning in Korea, Ieyasu became one of the guardians of his young son. The leading military figures in Japan now began to scheme against each other and civil war again broke out. Another of the advisers appointed by Hideyoshi was Ishisa Mitsunari, and it was he who formed the Western Army against Ieyasu. In 1600 Ieyasu defeated the Western Army in the decisive battle of Sekigahara, thereby achieving supremacy in Japan. In 1603 Emperor Go-Yozei, ruler only in name, gave Ieyasu the historic title of shogun (military governor) to confirm his pre-eminence. Japan was now united under Ieyasu's control. He worked hard to restore stability to Japan and encouraged foreign trade, which included the exchange of gifts with James I of England and other European rulers. It was only later, under Ieyasu's successors, that Japan effectively isolated itself from foreign contact. Ieyasu died on 17 April 1616. He was later deified and his mausoleum at Nikko became one of the most important shrines in Japan.