Ii Naomasa fought valiantly as the vanguard of the Eastern Army at Sekigahara in 1600, and was rewarded with 180,000 koku in Omi by Tokugawa Ieyasu. He died the following year from his battle wounds, but his son Naotsugu, with Naokata effectively organizing the construction, built Hikone Castle. The fame of the Ii Red Armour that Naomasa earned is the foundation of the Hikone domain's four centuries.