Partisans are armed fighters who do not belong to an organised army. They are usually organised in paramilitary groups to fight a power that occupied a certain area of claims rights to it. In World War II, partisan groups in several countries fought against the German occupation. In Greece, occupied by the German troops in 1941, the partisans organised a guerrilla war against the German occupation. However, the Greek partisan groups did not only fight the Germans, they fought among each other. The conflict between left-wing and right-wing partisan groups continued in the Greek Civil War from 1946 to 1949.