Why is the ninth month called September?
1610s, "hereditary commander of a Japanese army," from Japanese (sei-i-tai) shogun "(barbarian-subduing) chief" (late 12c.), sound-substitution for Chinese chiang chiin, literally "lead army."
Japanese military leaders who ruled the country from the twelfth to the nineteenth centuries. There was still an emperor in Japan under the shoguns, but he was reduced to a mere figurehead.