The Sawayama Domain was established in 1595 when Mitsunari ISHIDA, who displayed his uncommon shrewdness as Gobugyo under Hideyoshi TOYOTOMI, was transferred from the Omi Minakuchi Domain to his new territory with 194,000 koku crop yields.
佐和山藩は文禄4年（1595年）に豊臣秀吉のもとで五奉行として辣腕を振るっていた石田三成が、近江水口藩から移封されて19万4000石で入ることで立藩した。