The Greek city-states habitually waged war on each other, so there were endless examples. They desisted briefly to face off the Persian intervention in thee Greek world in the 5th Century, but before and after that the cities had continual disputes and wars. The most intense was the 27-year Peloponnesian War 431 to 404 BCE which pitted Athens and its empire against the Peloponnesian League led by Sparta.
Civil War Generals II happened in 1997.
Second English Civil War happened in 1648-02.
Sierra Leone Civil War happened on 1991-03-23.
Greek War of Independence happened in 1821.
Indian intervention in the Sri Lankan Civil War happened in 1987.
Civil war in Tajikistan happened in 1993.
Georgian Civil War happened in 1992.
Salvadoran Civil War happened in 1980.
Somali Civil War happened in 1996.
Piedmontese Civil War happened in 1639.
Castilian Civil War happened in 1368.
Paraguayan Civil War happened in 1947.
Laotian Civil War happened in 1953.
Liberators' civil war happened in -43.
Guatemalan Civil War happened in 1960.
Angolan Civil War happened in 1975.
Uruguayan Civil War happened in 1839.