 Scholar Mark Ravina used Yonezawa as a case study, in analysing the political status and conceptions of statehood and identity in the feudal domains of the Edo period (1603–1868).The region which later became Yonezawa Domain was held by the Date clan for much of the Sengoku period, from 1548 to 1591, when Toyotomi Hideyoshi came to power and declared the Date move to Iwadeyama in Mutsu Province.The Gamō clan were given Aizu to govern under the Uesugi, and "Tairō" Uesugi Kagekatsu gave his "karō" (advisor) Naoe Kanetsugu a 300,000 "koku" income.