Shugosho (provincial administration) (守護所)
Shogosho was the seat of the castle where Shugo (provincial constable) lived in medieval Japan. With the expansion of political power of Shugo, the functions of Kokuga (provincial government offices) were shifted to Shugosho.
In the early Kamakura period, functions of Shugo were limited to Taibon Sankajo (three major tasks of peacekeeping). Then, Shugosho were placed in different places from Kokuga, where the provincial government offices of Kokushi (provincial governors) appointed by the Imperial Court were. Shugo was not hereditary but a shift system, so Shogosho was generally moved according to the change of Shugo.
However, from the late Kamakura period, when functions of Shugo as peace preservation expanded to the administration of justice, authority of Shugo overcame Kokushi. Then, after the period of the Northern and Southern Courts (Japan), Shugo came to take control of the provinces. Also, Shugosho increasingly became fixed to one place according to the development of Shugo's hereditary succession.
Shogosho for hereditary Shugo were often placed in the home ground of the said samurai family, in Fuchu (provincial cities which consist of local governments as the core of the city), where the seat of the Kokuga was, or in other important spots for transportation or business. Due to fixation of Shugosho, the residences of chief retainers were located centered around the residence of Shugo, then markets and temples and shrines gathered around them. Then, they served as provincial cities.
In the Sengoku period (period of warring states), the emerging power resulted from the fall of Shugo daimyo (feudal lords) along with gekokujo (an inverted social order when the lowly reigned over the elite), or on the other hand, Sengoku daimyo (Japanese territorial lord in the Sengoku period) from old Shugo daimyo, who sloughed off the Shugo-ryogoku system (system that a Shugo dominates a manor) and established the government of the domain appeared as new rulers. However, some seats of Shugosho were still used as their home ground.