Short answers, pulled from the story.
The Greek Civil War took place from 1946 to 1949, although its roots lay in divisions that emerged during the Axis occupation of Greece from 1941 to 1944. The war formally ended on the 16th of October 1949, when KKE leader Nikolaos Zachariadis announced a ceasefire.
The Greek Civil War was fought between the royal government of the Kingdom of Greece and the Communist-led Democratic Army of Greece (DSE), the military wing of the Communist Party of Greece (KKE). The government was backed by Britain and the United States, while the DSE received support from Yugoslavia and Albania.
The Greek Civil War was the first proxy conflict of the Cold War and the first postwar example of Western Allied intervention in the internal affairs of a foreign country. It prompted the Truman Doctrine of 1947 and was shaped by the policy of containment suggested by US diplomat George F. Kennan in his Long Telegram of February 1946.
About 30,000 children were forcibly taken by the DSE from territories it controlled and sent to Eastern Bloc countries. A United Nations Special Committee confirmed that some children had been forcibly removed. More than 25,000 additional children, most with parents in the DSE, were placed in 30 child towns under the direct control of Queen Frederica. Many of the children taken to Eastern Bloc countries returned to Greece between 1975 and 1990.
The Greek Civil War ended in October 1949 after a combination of military defeats and the collapse of DSE's external support. In July 1949, Yugoslavia's Tito closed the border to the DSE and disbanded its camps inside Yugoslavia. General Alexander Papagos launched Operation Pyrsos in August 1949, forcing DSE divisions to retreat to Albania. On the 16th of October, KKE leader Zachariadis announced a ceasefire.
The Greek parliament unanimously recognized the 1946-1949 conflict as a civil war in 1989, through a law passed by a coalition government of Nea Dimokratia and the Coalition of Left and Progress. The law replaced the former official term Bandit War (Symmoritopolemos) with the designation Fighters of the DSE.