On 28 October 1940, Italy had declared war on Greece, beginning the
Greco-Italian War, expecting a swift victory. The invasion failed and the Italians were pushed back into Albania. On 6 April 1941, Germany intervened to support its struggling ally. The small Greek force defending the
Metaxas Line on the Greco–Bulgarian border was defeated by the better equipped and numerically superior German invasion force. The German penetration deep into Greece made further resistance at the Albanian front pointless, ending the
Battle of Greece in the favour of the Axis Powers. Greece was subjected to a
triple occupation by Germany, Italy and Bulgaria. In
Greek Macedonia the
KKE, communist-led
Greek People's Liberation Army (ELAS) emerged as the most powerful resistance organisation. In 1943, ELAS began disarming smaller non-communist guerrilla groups and incorporating them in its ranks or disbanding them. ELAS justified its action by accusing right-wing groups of collaboration with the German occupation authorities, a charge in which, according to SOE officer
Chris Woodhouse, "there was some justice [...] because Greek nationalists, like
Mihailović in
Yugoslavia, regarded the Germans as a less serious enemy than the Bulgarians or the Communists". EAM-ELAS constantly viewed any group not belonging to itself with distrust and accused them as "collaborators" but in many cases this backfired and became a self-fulfilling prophecy, as the remnants of the right-wing groups joined the Germans against ELAS. During the closing stages of the Axis occupation, Axis troops withdrew from northern Greece. Fearing reprisals from ELAS, members of the collaborationist
Security Battalions, right wing resistance groups (
EDES and
National Greek Army (EES) and their civilian supporters congregated at
Kilkis. The British supervised
Caserta Agreement, between ELAS and the
Greek government-in-exile, of September 1944 had characterised all units associated with the Security Battalions as enemy combatants and ordered them to surrender to the ΧΙ Division of ELAS. By October 1944, approximately 10,000 people had sought refuge in Kilkis. Security Battalion commanders debated whether they should entrench themselves in Kilkis or move. The decision was taken to remain in Kilkis, despite the fact that the local population was sympathetic to ELAS. On 30 October, the defenders took positions around Ano Apostoloi, Mesoi Apostoloi and Kato Apostoloi. The following day those positions were harassed by small bands of ELAS fighters. Later on Konstantinos Papadopoulos, one of the most powerful Security Battalion commanders, voiced his disagreement with the way the defences were organised. His unit of 1,500 men left for the village of Mouries, promising to return in the case of an attack on the city. ==Battle==