A coup d'état (/ˌkuːdeɪˈtɑː/; plural: coups d'état), also known as a coup, a putsch, or an overthrow, is the sudden deposition of a government,usually by a small group of the existing state establishment—typically the military—to depose the extant government and replace it with another body, civil or military. A coup d'état is considered successful when the usurpers establish their dominance. When the coup neither fails completely nor succeeds, a civil war is a likely consequence.

-Wikipedia