The Communist Party of Greece was founded in 1918 and later emerged as one of the region's most principled supporters of Soviet Union and the Third International. During the 1930s, the communists attempted to seize power by violent means, but were defeated. Although communist influence was largely subdued, the party continued its activities and, for example, took inspiration from Stalin's decisions to encourage Greek soldiers not to fight the attacks of Fascist Italy and start a civil war.
When Greece was occupied by Nazi Germany, communists emerged as a dominant force in the guerilla warfare against the invaders. This helped gain public sympathy, which the communists then used to engage in ruthless conflict with partisans supporting the legitimate Greek government. At the end of World War II, communist partisans attempted to seize all of Greek territory, but were rebuffed by British forces and nationalist partisans. The ensuing truce was short-lived as the communists again headed to overthrow the government. A bloody civil war followed, killing tens of thousands.
Communists resorted to overall terror to assert their authority. Their most serious crime was the kidnapping of 30 000 children and deporting them to communist countries. Parents attempting to rescue their children were shot. This crime has been recorded in N. Gage's renowned book „Eleni". Although communist resistance was eventually squashed, the Civil War legacy continued to divide Greek society for a long time.