According to Reinhart Koselleck, the eighteenth century witnessed the gradual and permanent separation of concepts of "civil war" and "revolution". Placing these ideas in a longer perspective – a longue durée that goes back to republican Rome and comes forward to our own times – challenges this narrative by showing that civil war was the genus of which revolution was only a species. This argument presented by David Armitage can help us to rethink the late eighteenth-century "Age of Revolutions"; it can also explain the confusion as we attempt to understand political violence in places like Egypt and Syria today.