A coup d'état ( ; , literally "blow of state"; plural: coups d'état, pronounced like the singular form), also known simply as a coup , or an overthrow, is the sudden and illegal seizure of a state, usually instigated by a small group of the existing government establishment to depose the established regime and replace it with a new ruling body. A coup d'état is considered successful when the usurpers establish their dominance and legitimacy. If a coup fails, a civil war may ensue.