Iemitsu Tokugawa was born on 12 August 1604. He was the second son of Tokugawa Hidetada; his mother was the daughter of Asai Nagamasa, a military leader of the province of Omi, and his wet nurse was Kasuga-no-tsubone. In childhood he went by the name Takechiyo.
Career
In 1614-15, when his father and grandfather marched west to attack and overthrow the forces of the Toyotomi family at Osaka Castle, he remained in Edo to guard Edo Castle, though still only a child. With his coming-of-age ceremony in 1620, he assumed the name Iemitsu. In 1623 he journeyed with his father to Kyoto and received commission from the imperial court to succeed his father in the position of shogun.