ABSTRACT
While the Dardanelles campaign remained at a stalemate in September 1915 and the Germans built up their submarine strength in the Mediterranean, the entire Balkan situation was about to be radically changed by the entry of Bulgaria into the war on the side of Germany and Austria. This also had its effect on the naval war in the Mediterranean for it resulted in a major new commitment for the British and French in the form of the Salonika expedition, provided new opportunities for the Austrians in the Adriatic, opened up direct rail communications between Germany and Constantinople and, finally, and perhaps inevitably, generated strong pressures for the liquidation of the Dardanelles campaign. The Germans and Austrians were eventually successful in the long diplomatic duel to win over Bulgaria and on 6 September concluded an alliance and military convention which included provisions for a combined German and Austrian military campaign to begin against Serbia within thirty days, which the Bulgarians were to join five days later. The Bulgarian army began its mobilization on 21 September and the Serbian government appealed to Greece, with whom it was bound by the treaty of May 1913 for assistance. This assistance was contingent, however, on the Serbians supplying 150,000 troops to any campaign, a requirement the outnumbered and hard-pressed Serbs could not now meet. The pro-Allied Prime Minister of Greece, Eleutherios Venizelos, suggested that the British and French supply this force and secured the consent of King Constantine for an Allied landing at Salonika with the objective of marching up the Vardar Valley to support the Serbs. The Greek political situation was extremely complicated and King Constantine was strongly opposed to actually joining the war. The Greeks publicly refused the Allied request to land at Salonika, despite the private assurances of Venizelos. Nevertheless, a British division and a French division began to land at Salonika on 3 October. Venizelos resigned on the 5th over King Constantine’s refusal to join the war and the succeeding cabinets of Alexandros Zaimis (6 October-5 November) and the more anti-Allied Stephanos Skouloudis held fast to the policy of neutrality. The German Eleventh Army and the Austrian Third Army under Field Marshal August von Mackensen began their offensive on 6 October and Belgrade fell on the 9th, while on the 11th two Bulgarian armies began their invasion. The British and French declared war on Bulgaria on the 15th and 16th and on the 21st the Allied naval forces bombarded Dedeagach and other points on Bulgaria’s Aegean coastline. The Allied forces at Salonika were placed under the command of General Sarrail and were reinforced by two French divisions with more British troops to follow. The original British and French plan to march up the Vardar Valley to support the Serbs did not appear very promising given the forces arrayed against them, and the now uncertain attitude of the Greek government with Venizelos removed from power added yet another element of great danger. There was a very real fear that the Allied troops might be attacked in their rear by the pro-German elements in the Greek army, sensing victory once it appeared likely that Serbia would be overrun. 1
