Iwatsuki was an important strongpoint of the
Odawara Hojo clan. However, following the destruction of that clan at the
Battle of Odawara of 1590, the territory came under the control of
Tokugawa Ieyasu, who assigned a 20,000
koku domain to one of his most trusted retainers,
Kōriki Kiyonaga. Following the
Siege of Osaka, his grandson
Kōriki Tadafusa was awarded with a promotion to the 35,000 koku
Hamamatsu Domain in 1619. The following year, in 1620, the
rōjū Aoyama Tadatoshi was awarded Iwatsuki with holdings of 55,000 koku. He subsequently fell from favor and was demoted to the 20,000
koku Ōtaki Domain in 1623.
Abe Masatsugu was transferred to Iwatsuki in 1638 from
Odawara Domain. The
Abe clan ruled Iwatsuki over the next five generations until 1681, gradually increasing their holdings to 95,000
koku. After their transfer to
Miyazu Domain, they were replaced by Itakura Shigetane (1681-1682),
Toda Tadamasa (1682-1686),
Matsudaira Tadachika (1696-1697)
Ogasawara Nagashige (1697-1710) and his son Ogasawara Nagahiro (1710-1711). The
Nagai clan was then awarded Iwatsuki, beginning with
Nagai Naohiro in 1711 and lasting for three generations until the clan was transferred to
Kanō Domain in 1756. Ōoka Tadamitsu (1709–1760), a distant relative of
Ōoka Tadasuke who had started as a 300
koku hatamoto, rose rapidly through the ranks and was eventually awarded Iwatsuki and 20,000
koku in 1756. His descendants remained at Iwatsuki until the
Meiji Restoration. The final daimyō of Iwatsuki, Ōoka Tadatsura (1847–1920) sided with the pro-imperial forces in the
Boshin War and made a viscount (
shishaku) in the
kazoku peerage system in the
Meiji period. The domain had a population of 38,404 people in 6,962 households per a census in 1870. ==Holdings at the end of the Edo period==