Civil war:
A civil war is a war in which parties within the same country or empire struggle for national control of state power. As in any war, the conflict may be over other matters such as religion, ethnicity, or distribution of wealth. Some civil wars are also categorized as revolutions when major societal restructuring is a possible outcome of the conflict. An insurgency, whether successful or not, is likely to be classified as a civil war by some historians if, and only if, organized armies fight conventional battles. Other historians state the criteria for a civil war is that there must be prolonged violence between organized factions or defined regions of a country (conventionally fought or not). In simple terms, a Civil War is a war in which a country fights another part of itself."
http://en.wikipedia.org/wiki/Civil_war