Every nation, much like other nations, contains it's own "Hidden Village", being the branches of military; samurai, shinobi, or any other chakra emitting group/s. Village Heads, go by Emperor/Empress, and shinobi village's go by "Sen" (仙, lit. leader); for instance if the village is known as the 'village hidden in the mountains', that perspective village's leader would be known as the 'Yamasen' (lit. mountain leader).