The Italian invasion from Albania on October 28, 1940, after making small initial gains, was stopped by the determined defense of Greek forces in the battles at the Elaia–Kalamas line and the Pindus Mountains. The unwillingness of Bulgaria to attack Greece, as the Italians had hoped, allowed the Greek High Command to transfer most of the mobilizing divisions intended for the garrisoning of Macedonia to the front, where they were instrumental in the Greek counteroffensive, launched on November 14. Greek forces crossed the border into Albania and took city after city despite facing a harsh winter, having inadequate supplies and facing Italian air superiority. By mid-January, Greek forces had occupied a quarter of Albania, but the offensive came to a standstill before it reached its objective, the port of Vlorë.