The Provisional Government of National Defence (), also known as the State of Thessaloniki (Κράτος της Θεσσαλονίκης), was a parallel administration, set up in the city of Thessaloniki by former Prime Minister Eleftherios Venizelos and his supporters during World War I, in opposition and rivalry to the official royal government in Athens.
The establishment of this second Greek state had its origins in the debate over Greece's entry into the war on behalf of the Entente, as advocated by Venizelos, or a Germanophile neutrality as preferred by King Constantine I. This dissension soon began to divide Greek society around the two leaders, beginning the so-called "National Schism". In August 1916, as parts of eastern Macedonia were not defended by the royal government against a Bulgarian invasion, Venizelist officers of the Hellenic Army launched an Entente-supported coup in Thessaloniki. After a brief hesitation, Venizelos and his principal supporters joined the uprising and began the establishment of a second Greek government in the north of the country, which entered the war on the side of the Entente. The National Defence government endured until June 1917, when the Entente powers forced Constantine I to abdicate, and allowed Venizelos to return to Athens as Prime Minister of a unified country. Nevertheless, the establishment of the National Defence government deepened the rift of the National Schism, which would plague Greek political life for over a generation, and contribute to the Asia Minor Catastrophe.
Background: Greece 1914–1916
Greece had emerged victorious from the 1912-1913 Balkan Wars, with her territory almost doubled, but found itself in a difficult international situation. The status of the Greek-occupied eastern Aegean islands was left undetermined, and the Ottoman Empire continued to claim them, leading to a naval arms race and mass expulsions of ethnic Greeks from Anatolia. In the north, Bulgaria, defeated in the Second Balkan War, harbored revanchist plans against Greece and Serbia. The two countries were bound by a treaty of alliance which promised military assistance in case of a Bulgarian attack, but in August 1914, the danger would emerge from a different quarter altogether: the Assassination of Archduke Franz Ferdinand led to the declaration of war by Austria-Hungary on Serbia and the outbreak of the First World War.
Greece, like Bulgaria, initially maintained neutrality, but as the war continued, both warring camps began wooing the two countries. At this point the first rifts appeared among the Greek leadership: 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.