The centuries-old civil wars in what was France, starting in the 1100s. Much of this war has been with outside powers- the Germans, for example, moved to the Rhone and to Calais, and the Scottish Empire still holds Brittany. As the feudal system died out, one noble side was replaced by republicans, and other noble states were replaced after that by varying levels of left-wing regimes. The varying states only united against foreign aggression- it is the only thing keeping France as an actual idea alive.
The war without end has become an integral part of French culture, and after 853 years, the wars (although interspersed with ceasefires and the like) are the French. The wars, however, may be drawing to a close, as Theosocialist forces move from their bases in Normandy and Paris down south, crushing monarchist, fascist and republican opposition.
(Damn, ninja'd.)
Anyways- The War of Ethiopian Supremacy.