A civil war is a war in which parties within the same culture, society or nationality fight against each other for the control of political power.

Some civil wars are 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 criterion for a civil war is that there must be prolonged violence between organized factions or defined regions of a country (conventionally fought or not).

Ultimately the distinction between a "civil war" and a "revolution" or any other name may be arbitrary, and is determined by usage. However the distinction between a "civil war" and "revolution" can be recognizable. The successful civil war of the 1640s in England which led to the (temporary) overthrow of the monarchy represented by Charles I became known as the English Civil War, which can be described, by Marxists and some historians, as the English Revolution. The successful insurgency of the 1770s in British colonies in America, with organized armies fighting battles, came to be known as the American Revolution. In the United States, and in American-dominated sources, the term 'the civil war' usually means the American Civil War, with other civil wars noted or inferred from context.

Factors such as nationalism, religion, and ideology played little role in pre-modern civil wars. Modern nationalists have commonly read past revolts (such as Scotland against England or Catalonia against Spain) as early stirrings of nationalism, the truth is that these conflicts were in fact feudal or dynastic rather than national. There are some pre-modern civil wars that can be seen as fueled by religion (the Jewish Revolts against Rome), but these can also be seen as revolts by a servile people against their oppressors or uprisings by local notables in an attempt to gain independence.  

• Warring States Period (China), 475?221 BC (this is not universally considered a civil war, but rather an international conflict. However each of the combatant states nominally acknowledged the authority of the Zhou kings of China, thus bringing them into one kingdom. This ended in 256 BCE, however this was a mere 35 years before the end of conflict)
• The Civil War of Carthage, 309?308 BC
• The Mercenary War, 241?237 BC
• Roman Republican civil wars, List of Roman Republic and Empire Civil Wars
• Three Kingdoms period, 184?280 The Han dynasty disintigrates into a period of warlordism after the Yellow Turban Rebellion and then, from 220?280, an extended conflict between three competing successor states.
• Later Three Kingdoms period, 892?936 The Kingdom of Silla of Korea was lost control of peninsula and the nation was divided by various warlords, until Wang Gun unifies the country.
• The Brothers' Civil War, 1067?1072 (The war between King Alfonso of Le?n and King Sancho of Castile)
• Civil war era in Norway, 1130?1240
• The Anarchy, 1135?1153 (refers to the disorder during the reign of King Stephen of England)
• Genpei War (Japan), 1180?1185
• Great Feudal War in Russia, 1425?1453
• English Wars of the Roses, c. 1455?1485
• Onin War (Japan), 1467?1477
• Sengoku Period (Japan), 1467?1615
• French Wars of Religion, 1562?1598
• Rokosz of Zebrzydowski, 1606?1609 in the Polish-Lithuanian Commonwealth
• Wars of the Three Kingdoms (England, Ireland, Scotland) 1639?1651 involved a number of civil wars:
• Irish Confederate Wars some parts of which were a civil war.
• English Civil War, 1642?1651
• Scotland in the Wars of the Three Kingdoms, to some extent a civil war, 1644?1652
• First English Civil War 1642?1646
• Second English Civil War 1648?1649
• Third English Civil War 1650?1651
• Rokosz of Lubomirski, 1665?1666 in the Polish-Lithuanian Commonwealth
• War of Reform (Mexico) 1857?1861
• Zulu Civil War, 1817?1819
• Maori War (New Zealand) 1845?1872
• Taiping Civil War (China), 1851?1864
• American Civil War, 1861?1865
• Klang War; also known as Selangor Civil War, 1867?1874
• Boshin War (Japan), 1868?1869
• Satsuma Rebellion (Japan), 1877
• Jementah Civil War, 1879
• Russian Civil War, 1917?1921
• Finnish Civil War, 1918
• Irish Civil War, 1922?1923
• Chinese Civil War, 1928?1937, 1945?1949
• Austrian Civil War, February 12 to February 16, 1934
• Spanish Civil War, 1936?1939
• Greek Civil War, 1946?1949
• Paraguayan Civil War, 1947
• Palestinian Civil War, 1947-48
• Costa Rica Civil War, 1948
• Korean Civil War, 1950?1953
• Vietnamese Civil War, 1954?1975
• Guatemalan Civil War, 1960?1996
• Indonesian Civil War, 1965?1966
• Nigerian Civil War, 1967?1970
• Pakistani Civil War, 1971
• Lebanese Civil War, 1975?1990
• Mozambican Civil War, 1975?1992
• Sandinista Civil War, 1979?1989
• Salvadoran Civil War (El Salvador), 1979?1991
• Albanian rebellion in Macedonia 1999
• Afghan Civil War, 1992?2001
• First and Second Congo Wars (1996?1997, 1998?2002)

Contemporary civil wars

The following civil wars are ongoing or ended in the past decade, as of 2006. Some of them may be classified as insurrections, etc., rather than full civil wars, as they fade into the past. 

• Afghan Civil War, 1992?2001, armed conflicts persist
• Algerian Civil War, 1991?2002, conflicts persist
• Angolan Civil War, 1974?1989, 1995?1997, 1998?2002
• Burundi Civil War, 1988?1991, 1993?2005
• Cabindan Civil War, Angola, 1975?2006
• Cambodia, 1978?1993, 1997?1998
• Casamance Conflict, Senegal, 1990?present
• Colombian armed conflict, 1964?present
• Congo Civil War, 1996?1997, 1998?2003
• C?te d'Ivoire Civil War, 1999?2000, 2002?present
• Darfur Conflict, Sudan, 2003?present
• East Timor/Indonesia, 1975?1999
• Georgian Civil War, Abkhazia, South Ossetia in Georgia, 1988?present
• Guatemalan Civil War, 1960?1996
• Guinea-Bissau Civil War, 1998?1999
• Haiti Rebellion, 2004
• Iraq Civil War, 2003(?)?present
• Kashmir Conflict, 1989?present
• Kurdistan, Kurdish Democratic Party, Patriotic Union of Kurdistan, 1961?1970, 1988?2003
• Liberian Civil War, 1989?1996, 1999?2003
• Nepalese Civil War, 1996?2006
• Northern Irish civil war, 1969?1998 (Considered ongoing by extremist minority gropus)
• Rwandan Civil War, 1990?1994
• Sierra Leone Civil War, 1991?2002
• Somali Civil War, 1991?present
• Sri Lankan Civil War, 1983?present
• Sudanese Civil War, 1955?1972, 1983?2005
• Tajikistan Civil War, 1992?1997
• Ugandan Civil War, 1987?present
• Yemen Civil War, 1979?1989, 1994, 2000s
• Yugoslav Wars, 1991?1995, Breakup ? Slovenia, Croatia, Bosnia (1st NATO intervention), Kosovo (2nd NATO intervention), Pre?evo valley, Macedonia ? Kosovo War 1996?1999

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