The upheaval resulted in the further weakening of central authority, and throughout Japan, regional lords, called daimyōs, rose to fill the vacuum. In the course of this power shift, well-established clans such as the Takeda and the Imagawa, who had ruled under the authority of both the Kamakura and Muromachi bakufu, were able to expand their spheres of influence. There were many, however, whose positions eroded and were eventually usurped by more capable underlings. This phenomenon of social meritocracy, in which capable subordinates rejected the status quo and forcefully overthrew an emancipated aristocracy, became known as gekokujō (下克上), which means "low conquers high".