Tairō.

About Tairō

Tairō was a high-ranking official position in the Tokugawa shogunate government of Japan, roughly comparable to the office of prime minister. The tairō presided over the governing rōjū council in the event of an emergency. A tairō was nominated from among the fudai daimyōs, who worked closely with the Tokugawa traditionally. Generally, the office holder was the shogunate's chief policymaker, and provided Japan with a capable temporary leader in the absence of a shōgun, or in the event that the shōgun was incapacitated.