As part of the Treaty of London (1915), by which Italy left the Triple Alliance (with Germany and Austria-Hungary) and joined France, Great Britain and Russia in the Triple Entente, Italy was promised the Dodecanese and, if the partition of the Ottoman Empire were to occur, land in Anatolia including Antalya and surrounding provinces presumably including Smyrna.

[5] But in later 1915, as an inducement to enter the war, British Foreign Secretary Edward Grey in private discussion with Eleftherios Venizelos, the Greek Prime Minister at the time, promised large parts of the Anatolian coast to Greece, including Smyrna.

[5] Venizelos resigned from his position shortly after this communication, but when he had formally returned to power in June 1917, Greece entered the war on the side of the Entente.

[7] The Italian position was that Smyrna was rightfully their possession and so the diplomats would refuse to make any comments when Greek control over the area was discussed.

[7] To further this aim, he brought in a set of experts, including Arnold J. Toynbee, to discuss how the zone of Smyrna would operate and what its impacts would be on the population.

"[5] Both to protect local Christians and also to limit increasing Italian action in Anatolia, French Prime Minister Georges Clemenceau and U.S. President Woodrow Wilson supported a Greek military occupation of Smyrna.

Smith reports that this news was "received with great emotion" by the Greek population of the city while thousands of Turkish residents gathered in the hill that night lighting fires and beating drums in protest.

[8] An inexperienced colonel was in charge of the operation and neither the appointed high commissioner nor high-ranking military individuals were there for the landing, resulting in miscommunication and a breakdown of discipline.

British officers in the harbor reported seeing Greek troops bayoneting multiple Turkish prisoners during the march and then saw them thrown into the sea.

Violence continued the next day and for the next months as Greek troops took over towns and villages in the region and atrocities were committed by both ethnic groups, notably the Battle of Aydın on 27 June 1919.

[8] At about the same time, British Field Marshal George Milne was tasked by the allies with devising a solution to Italian and Greek tension in the Menderes River Valley.

Stergiadis immediately punished the Greek soldiers responsible for violence on 15–16 May with court martial and created a commission to decide on payment for victims (made up of representatives from Great Britain, France, Italy and other allies).

On 14 July 1919, the acting foreign secretary sent a long critical telegraph to Venizelos suggesting that Stergiadis be removed and writing that "His sick neuroticism has reached a climax.

"[8] Venizelos continued to support Stergiadis despite this opposition, while the latter oversaw a number of projects planning for a permanent Greek administration of Smyrna.

This situation resulted after a decision by the Supreme Allied Council that all movements of the Greek army had to be approved by Field Marshal George Milne.

Apart from the kaza of Smyrna and the adjacent area of Ayasoluk which were under the direct control of the Smyrna High Commission, the remaining zone was divided into one province (Greek: Νομαρχία Nomarchia): that of Manisa, as well as the following counties (Greek: Υποδιοικήσεις Ypodioikiseis): Ödemiş, Tire (Thira), Bayındır (Vaindirion), Nympheon, Krini, Karaburna, Sivrihisar, Vryula, Palea Phocaea, Menemen, Kasaba, Bergama and Ayvali.

[17] A survey conducted by the refugees department indicated that more than 150 towns and villages along the coastal area (from Edremit to Söke) had been destroyed during World War I.

[19] In total, 100,000 Greeks who had lost their land during World War I, many a result of Ottoman discrimination, were resettled under Stergiadis, given generous credit, and access to farm tools.

[8] Following the Treaty of Sèvres, all sections of the Ottoman administration that dealt with issues pertaining to Muslim religion, education and family affairs were organized by the High Commission.

[20] Under this context a special polytechnic school was established in Smyrna which soon operated with 210 Muslim students and with costs covered by the Greek administration.

Early in July 1920, the allies approved operations by the Greeks to take over Eastern Thrace and territory around Smyrna as part of ongoing hostilities with the Turkish Nationalist movement.

[7] In early 1920, Lloyd George was able to convince the new French Prime Minister, Alexandre Millerand to accept Greek control of Smyrna, but under Turkish suzerainty.

French pressure and divisions within the British government resulted in Lloyd George accepting a time frame of 5 years for Greek control over Smyrna with the issue to be decided by the League of Nations at that point.

Jensen summarizes the violence writing that "The Turkish population was subjected to horrible atrocities by the retreating troops and accompanying civilian Christian mobs.

The pursuing Turkish cavalry did not hesitate in kind on the Christian populace; the road from Uşak to Smyrna lay littered with corpses.

"[5] Greek troops evacuated Smyrna on 9 September 1922 and a small allied force of British entered the city to prevent looting and violence.