On 28 October 1940, Italy declared war on Greece, expecting a swift victory but the invasion failed and the Italians were pushed back into Albania. As the war dragged on, on 6 April 1941 Germany was forced to intervene 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 Germans. The German penetration deep into Greece made further resistance at the Albanian front pointless, ending the Battle of Greece in the favor of the Axis Powers. Greece was subjected to a triple occupation by Germany, Italy and Bulgaria. Unlike Italy and Germany, Bulgaria did not administer eastern Macedonia and the parts of Western Thrace it controlled through Greek collaborators, but annexed the area to form the province of Belomorie. The Bulgarian language was made compulsory in all administrative matters, as well as in the education and liturgy. Businessmen were forced to accept Bulgarian partners or even hand their property over to Bulgarian control. Efforts to promote Bulgarisation were also enacted in the German-controlled Greek Macedonia, through the creation of Bulgarian clubs in all major towns. The first resistance organization in northern Greece was founded in May 1941; "Eleutheria" (Liberty) united people from across the political spectrum ranging from communists to Venizelists. The group was short-lived, as internal political disagreements and the work of Axis intelligence services suppressed its activities, but bands belonging to the Communist-led National Liberation Front (EAM) and its Greek People's Liberation Army (ELAS), continued to emerge in the region.