Hamamatsu Domain
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.