The shugo in the Muromachi period were initially (around the mid 14th century) appointed by the Muromachi bakufu (Japanese feudal government headed by a shogun) once in several years, which resulted in the comparatively frequent alternation of the shugo-shiki (the post of shugo).
室町期の守護は、当初（14世紀中葉）、室町幕府から数年ごとに補任されており、守護職の交替は比較的頻繁に行われていた。