Tokugawa Iemitsu (徳川 家光; 12 August 1604 – 8 June 1651) was a Japanese samurai, daimyo and the third shōgun of the Tokugawa dynasty. He was the eldest son of Tokugawa Hidetada with Oeyo, and the grandson of Tokugawa Ieyasu. Lady Kasuga was his wet nurse, who acted as his political adviser and was at the forefront of shogunate negotiations with the Imperial court. Iemitsu ruled from 1623 to 1651; during this period he crucified Christians, expelled all Europeans from Japan and closed the borders of the country, a foreign policy that continued for over 200 years after its institution.
Tokugawa Iemitsu was born prematurely on 12 August 1604. He was the eldest son of Tokugawa Hidetada and grandson of the last great unifier of Japan, the first Tokugawa shōgun Tokugawa Ieyasu. He was the first member of the Tokugawa family born after Tokugawa Ieyasu became shōgun. (There was some rumour said that he was not Hidetada's son but Ieyasu's son with Kasuga no Tsubone).
Not much is known of Iemitsu's early life; his childhood name was Takechiyo (竹千代). He had two sisters, Senhime and Masako, and a brother, who would become a rival, Tadanaga. Tadanaga was his parents' favorite. However, Ieyasu made it clear that Iemitsu would be next in line as shōgun after Hidetada.
He was said to have been sickly from birth.
An obsolete spelling of his given name is Iyemitsu.
Father: Tokugawa Hidetada (徳川 秀忠), May 2, 1581 – March 14, 1632
Mother: Lady Oeyo (於江与; 1573 – September 15, 1626)
Sibling from Mother: Toyotomi Sadako (1592–1658), adopted by Toyotomi Hideyoshi and Yodo-dono later married Kujō Yukiie, daughter of Toyotomi Hidekatsu
Wet nurse: Lady Kasuga (春日局, Kasuga no Tsubone, 1579 – October 26, 1643)
Wife: Takatsukasa Takako (1622–1683) later Honriin, Takatsukasa Nobufusa's daughter
Concubine: Ofuri no Kata (d. 1640) later Jishōin (自証院)
Chiyohime (千代姫, 29 April 1637 – 10 January 1699), first daughter
Concubine: Oraku no Kata (1621–1653) later Hōjuin (宝樹院), Aoki Toshinaga's daughter (青木利長娘)
Tokugawa Ietsuna (徳川 家綱, 7 September 1641 – 4 June 1680), first son
Concubine: Omasa no Kata (おまさの方)
Tokugawa Kamematsu (17 April 1643– 2 September 1647), second son
Concubine: Onatsu no Kata (順性院; 1622–1683) later Junshōin (順性院), Fujieda Shigeya's daughter (藤枝重家娘)
Tokugawa Tsunashige (徳川 綱重, 28 June 1644 - 29 October 1678), third son