Tadamune was born as Torakikumaru (虎菊丸) later Sōjirō (総次郎) the second son of
Date Masamune. Although he was the second son, his elder half-brother Date Hidemune was born by Lady Iisaka, a concubine, and was thus not eligible to rule. At the age of seven, he was betrothed to Ichi-hime, the 5th daughter of
Tokugawa Ieyasu; however, she died three years later, and he was betrothed again to the daughter of
Ikeda Terumasa, who was also Ieyasu's grand-daughter. In 1611,
shōgun Tokugawa Hidetada presided over his
genpuku ceremony, and he received
courtesy title was
Mimasaka-no-kami, and Senior Fifth Rank, Lower Grade
Court rank. He also received permission from the
shōgun to use the
Matsudaira surname as an honorific. At the time of the 1614
Siege of Osaka, he accompanied his father in the train of Tokugawa Ieyasu, and it was by order of Ieyasu that Date Hidemune was ordered to establish an independent branch of the Date clan at
Uwajima in
Shikoku with a
kokudaka of 100,000
koku, whereas Date Tadamune was confirmed as heir to the main Date line at Sendai. Tadamune was elevated to Junior Fourth Rank, Lower Grade, and given the honorary title of
chamberlain in 1616. In 1624, his courtesy title was changed to
Echizen-no-kami, and changed again in 1626 to
Sakonoe-gon-shōshō (General of the Left Guards). On Masamune's death in June 1636, he became
daimyō, and entered
Aoba Castle in Sendai for the first time in August of the same year. He immediately took over the reins of government by replacing two of the six
bugyōs, and re-establishing a multi-person system of magistrates and inspectors to provide more oversight and to eliminate corruption and arbitrary rule. He followed this the following year by publishing a new code of rules and regulations for the domain. In 1639, his courtesy title was changed to
Mutsu-no-kami. In terms of finances, from 1640 to 1643 he ordered a complete re-survey of the domain, bringing units of measurements in line with the nationwide standards used by the Tokugawa shogunate. This was accompanied by large scale
land reform. Tadamune also established a system whereby the domain purchased all rice produced in the domain, and reselling in
Edo, paying the farmers in advance. This encouraged the opening of new rice lands. During Tadamune's tenure,
Sendai Castle was completed, and he sponsored the construction of numerous temples and shrines, including the
Zuihōden in 1637 and the
Sendai Tōshōgū in 1654. On Tadamune's death on 12 July 1658, one of his senior retainers, Furuuchi Shigehiro, committed ritual suicide (
junshi). Tadamune's sixth son
Date Tsunamune became
daimyō of Sendai. == Family ==