The Noemvriana (, "November Events") of , or the Greek Vespers (after the Sicilian Vespers), was a political dispute which led to an armed confrontation in Athens between the royalist government of Greece and the forces of the Allies over the issue of Greece's neutrality during World War I.

Friction existed between the two sides from the beginning of World War I. The unconditional surrender of the border fortress of Roupel in May 1916 to the Central Powers' forces, mainly composed of Bulgarian troops, was the first event that led to the Noemvriana. The Allies feared the possibility of a secret pact between the Greek royalist government and the Central Powers. Such an alliance would endanger the Allied army in Macedonia bivouacking around Thessaloniki since the end of 1915. Intensive diplomatic negotiations between King Constantine I and Allied diplomats took place throughout the summer. The king wanted Greece to maintain her neutrality, a position that would favor the Central Powers plans in the Balkans while the Allies wanted demobilization of the Hellenic army and the surrender of war materiel equivalent to what was lost at Fort Roupel as a guarantee of Greece's neutrality. By the end of the summer of 1916, the failure of negotiations, along with the Bulgarian Army's advance in eastern Macedonia and the Greek government's orders for the Hellenic army not to offer resistance, led to a military coup by Venizelist military officers in Thessaloniki with the support of the Allies. The former Prime Minister Eleftherios Venizelos, who from the very beginning supported the Allies, established a provisional government in northern Greece. He began forming an army to liberate areas lost to Bulgaria, but this effectively split Greece into two entities.

Noemvriana

The inclusion of the Hellenic army along with Allied forces, as well as the division of Greece, sparked several anti-Allied demonstrations in Athens. In late October, a secret agreement was reached between the king and the Allied diplomats. The pressure from the military advisers forced the king to abandon this agreement. In an attempt to enforce their demands, the Allies landed a small contingent in Athens on . However, it met organized resistance and an armed confrontation took place until a compromise was reached at the end of the day. The day after the Allied contingent evacuated from Athens, a royalist mob began rioting throughout the city, targeting supporters of Venizelos. The rioting continued for three days, and the incident became known as the Noemvriana in Greece, which in the Old Style calendar occurred during the month of November. The incident drove a deep wedge between the Venizelists and the royalists, bringing closer what would become known as the National Schism.

Noemvriana

Following the Noemvriana, the Allies, determined to remove Constantine I, established a naval blockade to isolate areas which supported the king. After the resignation of the king on 15 June 1917, Greece unified under a new king, Alexander, Constantine I's son, and the leadership of Eleftherios Venizelos. It joined World War I on the side of the Allies. By 1918, the mobilized Hellenic Army provided the numerical superiority the Allies needed on the Macedonian front. The Allied army shortly thereafter defeated the Central Powers forces in the Balkans, followed by the liberation of Serbia and the conclusion of World War I.

Noemvriana

Background

Greece emerged victorious after the 1912–1913 Balkan Wars, with her territory almost doubled. The unstable international political climate of the early 20th century placed Greece in a difficult position. The ownership of the Greek occupied eastern Aegean islands was contested by the Ottoman Empire which claimed them as their own. In the north, Bulgaria, defeated in the Second Balkan War, was engineering revanchist strategies against Greece and Serbia. The assassination of Archduke Franz Ferdinand of Austria in Sarajevo precipitated Austria-Hungary's declaration of war against Serbia. This caused Germany and Austria-Hungary, and countries allied with Serbia (the Triple Entente) to declare war on each other, starting World War I.

Greece, like Bulgaria, initially maintained neutrality during the conflict. The Greek leadership was divided between the Prime Minister Eleftherios Venizelos, who supported Great Britain on the side of the Allies and King Constantine who was educated in Germany and married to the Kaiser's sister. The king admired Prussian militarism and was anticipating a quick German victory. The king wanted Greece to remain neutral in the conflict, a strategy favorable to Germany and the Central Powers.