A society that has no effective channels for settling political and economic grievances among its classes and parties may erupt in civil war. The term may be a misnomer in so far as civil refers only to civilians taking part, since military units of various types may join in. Such wars are not likely to show civility either, often being characterized by intense fratricidal hatreds. Those opposed to the government may be termed insurgents, revolutionaries, counter-revolutionaries, resistance fighters, guerrillas, and other names, depending on circumstances. Civil wars may involve sabotage, terrorism and other crimes. Civil war is recognizable when the insurgents do not disperse but manage to hold a territory, or when the government in power invokes martial law. Not all civil wars have the overthrow of the government as their intention, although this is always the aim of revolutions; some have the intent of forcing legislative changes or of securing powers or privileges which are felt due.
In European history, civil war is traceable from the time of the Greeks and Romans. The Roman Civil Wars brought the Emperor Augustus to power. The English Civil War (1642-51) resulted in King Charles' execution. The War of Independence that the American colonies fought with England, the French Revolution, the American Civil War, the Revolution in the USSR, the Boxer Rebellion, and many others may be cited among other instances. The Spanish Civil War, the Greek Civil War and the Algerian Civil War are more recent examples. The term civil war may be indiscriminately applied as as synonym for the broad class of intrasocietal military conflicts that have occurred in different forms in Latin America, Africa and Asia in recent years.