Prime Minister Eleftherios Venizelos, at the helm since 1910 of a modernising government looking towards the British and French models, supported entry in the war on the side of the Entente, while King Constantine I, who had been educated in Germany, married to Kaiser Wilhelm II's sister and a deep admirer of Prussian militarism, anticipated a German victory. Aware that Greece was vulnerable to the British Fleet, he advocated a course of neutrality. In early 1915 the British offered Greece "territorial concessions in Asia Minor" if it would participate in the upcoming Gallipoli Campaign. Venizelos supported this idea, but run into the opposition from the King and his military advisors. As a result, Venizelos submitted his resignation on , and was replaced by a led by Dimitrios Gounaris. The Liberal Party won the subsequent May 1915 elections and Venizelos again formed a on . When Bulgaria mobilized against Serbia in September 1915, Venizelos ordered a Greek counter-mobilization and called upon the Anglo-French to establish themselves in Thessaloniki (then widely known as Salonica) as to aid Serbia. Indeed, the Allies began landing on 22 September 1915 and started entrenching themselves at the . The King unconstitutionally dismissed Venizelos and the parliament, making the breach between the two men and their followers irreparable. The Liberals boycotted the December 1915 elections. In the same month, the French, with the permission of Venizelos, occupied Corfu, where the remains of the Serbian Army were gathered before being sent to Thessaloniki. In view of these events, a clandestine "Revolutionary Committee of National Defence" was formed in Thessaloniki by a group of prominent Liberals and representatives of all over Macedonia, including Konstantinos Angelakis (mayor of Thessaloniki), and (representatives of Thessaloniki), and (representatives of Serres), Nikolaos Manos (representative of Kozani), Panayiotis Grekos (representative of Florina), (representative of Drama), Major General Emmanouil Zymvrakakis and others. The group acknowledged Venizelos as its leader, and began approaching officers of the Army and the Cretan Gendarmerie. During the following year, Greece's official governments were hard-pressed to maintain the country's neutrality. The final straw came when, on , the Athens government, succumbing to German pressure, ordered the surrender of the vital Rupel Fortress to the Germans and their Bulgarian Allies. In response, on , the pro-Entente Venizelists imposed martial law, effectively abolishing royal sovereignty in all of northern Greece. On , the Bulgarian invasion of eastern Macedonia commenced, facing little resistance, since the