征夷大将军在日本历史上，原为大和朝廷为对抗虾夷族所设立的临时的高级军官职位，本应于停战时即功成身退。「夷」其实是指曾在本州和北海道居住的虾夷族（阿伊努族），而「将军」一词指军阶中的高级领导职。征夷大将军的衙门称为幕府，故中文俗称征夷大将军为「幕府将军」，也常简称其为「将军」。

12世纪末，幕府将军转为所有武士与军人的首领、总代表。1192年，源赖朝出任征夷大将军，创立镰仓幕府，一时间能够统领各地诸侯与军人，故一直保留着将军之头衔，以后的幕府将军皆袭用「征夷大将军」之官位。由1192年开始，大部分幕府将军取代日本皇室与天皇，掌握日本实际政权，直到1868年明治维新为止。

A Shogun(将軍,Shōgun, [ɕoːɡu͍ɴ], "general", literally "military commander") was a hereditary military dictator in Japan during the period from 1192 to 1867. In this period, the shoguns were the de facto rulers of the country; although nominally they were appointed by the Emperor as a ceremonial formality. The Shogun held almost absolute power over territories through military means, in contrast to the concept of a colonial governor in Western culture. Nevertheless, an unusual situation occurred in the Kamakura period (1199-1333) upon the death of the first shogun, whereby the Hōjō clan's hereditary titles of Shikken and Tokuso (1256-1333) monopolized the shogunate, collectively known as the Regent Rule(執権政治). The shogun during this period met the same fate as the Emperor and was reduced to a figurehead until a coup in 1333, when the shogun was restored to power.