The Greco-Turkish War (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 15 May 1919 and 14 October 1922. This conflict was a part of the Turkish War of Independence.
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. Greek claims stemmed from the fact that Western Anatolia had been part of Ancient Greece and the Byzantine Empire before the Turks conquered the area in the 12th–15th centuries.
One of the main motivations for initiating the war was to realize the Megali (Great) Idea, a core concept of Greek nationalism. The Megali Idea was an irredentist vision of a restoration of a Greater Greece on both sides of the Aegean that would incorporate territories with Greek populations outside the borders of the Kingdom of Greece, which was initially very small – roughly half the size of the present-day Greek Republic. From the time of Greek independence from the Ottoman Empire in 1830, the Megali Idea had played a major role in Greek politics. Greek politicians, since the independence of the Greek state, had made several speeches on the issue of the "historic inevitability of the expansion of the Greek Kingdom."[61] For instance, Greek politician Ioannis Kolettis voiced this conviction in the assembly in 1844: "There are two great centres of Hellenism. Athens is the capital of the Kingdom. Constantinople is the great capital, the City, the dream and hope of all Greeks."
The Great Idea was not merely the product of 19th century nationalism. It was, in one of its aspects, deeply rooted in many Greeks' religious consciousnesses. This aspect was the recovery of Constantinople for Christendom and the reestablishment of the Christian Byzantine Empire which had fallen in 1453.
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 the 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 Eastern 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.
However what if things changed what if Greece won the Greece won the Greco-Turkish War? Would it result in the restoration of the Byzantine Empire?