1911 Encyclopædia Britannica/Shogun
SHOGUN (Japanese for “generalissimo”), in Japan, originally merely the style of a general in command in the field, a title which only gradually came into existence at the beginning of the 8th century, the mikado himself having previously been regarded as the only authority. The rise of a military class and of shoguns (generals) was a development coincident with the division of supremacy between the Minamoto and Taira clans (see Japan: History). In 1192 the emperor Takahira made the Minamoto leader, Yoritomo, a Sei-i-tai-shogun (“barbarian-subjugating generalissimo”) or general-in-chief, and this office became stereotyped in the hands of successive great military leaders, till in 1603 Lyéyasu Tokugawa became shogun and established the Tokugawa dynasty in power. The shogunate from that time till 1867 exercised the de facto sovereignty in Japan, though in theory subordinate to the mikado. The revolution of 1867 swept away and abolished the shogunate and restored the mikado's supreme authority.
The term “Tycoon,” which was commonly used by foreigners in the 19th century, is merely a synonym for shogun, being the English rendering of the Japanese taiko or taikun, “great lord.”