The final act of the Greco-Turkish War, the Great Fire of Smyrna, commences.

The burning of Smyrna (Greek: , "Smyrna Catastrophe"; Turkish: 1922 zmir Yangn, "1922 Izmir Fire"; Armenian: , Zmyuno Mets Hrdeh) destroyed much of the port city of Smyrna (modern zmir, Turkey) in September 1922. Eyewitness reports state that the fire began on 13 September 1922 and lasted until it was largely extinguished on 22 September. It began four days after the Turkish military captured the city on 9 September, effectively ending the Greco-Turkish War, more than three years after the landing of Greek army troops at Smyrna on 15 May 1919. Estimated Greek and Armenian deaths resulting from the fire range from 10,000 to 125,000.Approximately 80,000 to 400,000 Greek and Armenian refugees crammed the waterfront to escape from the fire. They were forced to remain there under harsh conditions for nearly two weeks. Turkish troops and irregulars had started committing massacres and atrocities against the Greek and Armenian population in the city before the outbreak of the fire. Many women were raped. Tens of thousands of Greek and Armenian men were subsequently deported into the interior of Anatolia, where most of them died in harsh conditions.The fire completely destroyed the Greek and Armenian quarters of the city; the Muslim and Jewish quarters escaped damage. There are different accounts and eyewitness reports about who was responsible for the fire; most sources and scholars attribute it to Turkish soldiers setting fire to Greek and Armenian homes and businesses, while a few, pro-Turkish sources hold that the Greeks and Armenians started the fire either to tarnish the Turks' reputation or deny them access to their former homes and businesses. Testimonies from Western eyewitnesses were printed in many Western newspapers.

The Greco-Turkish War of 1919–1922 was fought between Greece and the Turkish National Movement during the partitioning of the Ottoman Empire in the aftermath of World War I, between May 1919 and October 1922.

The Greek campaign was launched primarily because the western Allies, particularly British Prime Minister David Lloyd George, had promised Greece territorial gains at the expense of the Ottoman Empire, recently defeated in World War I, as Anatolia had been part of Ancient Greece and the Byzantine Empire before the Ottomans captured the area. The armed conflict started when the Greek forces landed in Smyrna (now İzmir), on 15 May 1919. They advanced inland and took control of the western and northwestern part of Anatolia, including the cities of Manisa, Balıkesir, Aydın, Kütahya, Bursa and Eskişehir. Their advance was checked by Turkish forces at the Battle of Sakarya in 1921. The Greek front collapsed with the Turkish counter-attack in August 1922, and the war effectively ended with the recapture of Smyrna by Turkish forces and the great fire of Smyrna.

As a result, the Greek government accepted the demands of the Turkish National Movement and returned to its pre-war borders, thus leaving East Thrace and Western Anatolia to Turkey. The Allies abandoned the Treaty of Sèvres to negotiate a new treaty at Lausanne with the Turkish National Movement. The Treaty of Lausanne recognized the independence of the Republic of Turkey and its sovereignty over Anatolia, Istanbul, and Eastern Thrace. The Greek and Turkish governments agreed to engage in a population exchange.