Shugo

, commonly translated as “(military) governor,” “protector,” or “constable,” was a title given to certain officials in feudal Japan. They were each appointed by the "shōgun" to oversee one or more of the provinces of Japan. The position gave way to the emergence of the "daimyōs" (大名, feudal lords) in the late 15th century, as "shugo" began to claim power over lands themselves, rather than serving simply as governors on behalf of the shogunate.
The post is said to have been created in 1185 by Minamoto no Yoritomo to aid the capture of Yoshitsune, with the additional motivation of extending the rule of the shogunate government throughout Japan. The "shugo" (military governors) progressively supplanted the existing "kokushi" (civil governors), who were appointed by the Imperial Court in Kyoto. Officially, the "gokenin" in each province were supposed to serve the "shugo", but in practice, the relationship between them was fragile, as the gokenin were vassals of the "shōgun" as well.
"Shugo" often stayed for long periods in the capital, far from their province, and were sometimes appointed "shugo" for several provinces at the same time. In such cases, a deputy "shugo", or "shugodai" (守護代), was appointed.
Over time, the powers of some "shugo" grew considerably. Around the time of the Ōnin War (1467–1477), conflicts between "shugo" became common. Some "shugo" lost their powers to subordinates such as the "shugodai", while others strengthened their grip on their territories. As a result, at the end of the 15th century, the beginning of the Sengoku period, the power in the country was divided amongst lords of various kinds ("shugo", "shugodai", and others), who came to be called "daimyōs".
Famous "shugo" and "daimyō" clans of the Muromachi period.
Below is a list of some of the major clans that produced "shugos" and "daimyōs" during the Muromachi period, as well as the regions over which they ruled.