The northern Greek city of Salonica—Thessaloniki to the Greeks—passed through Roman and Byzantine hands before falling to the Ottomans in 1430, which is the starting point of Mark Mazower's Salonica, City of Ghosts: Christians, Muslims and Jews, a chronicle 20 years in the making. At the geographical heart of the Ottoman Empire, Salonica was among its largest ports and most vital economic centers until the 18th century, when several episodes of the plague, along with a shift of trade routes to the rising Turkish port of Izmir, damaged the city's fortunes. By then, however, it had developed what Mazower calls a multiconfessional community whose many religions and ethnic groups mingled freely; the city, for example, was home to the ma'min, Sephardic Jews who followed the false messiah Sabbetai Sevi into Islam and practiced both Jewish and Muslim rites. This diversity persisted until Greek nationalists captured Salonica in 1912. A forced population exchange with republican Turkey in the 1920s emptied the city of its Muslims..
Mark Mazower's Salonica, City of Ghosts: Christians, Muslims, and Jews, 1430-1950 has this to say on the situation in 1912/13:
As it marched towards Salonica across the Vardar valley, the Hellenic Army was far less violent towards Muslim civilians than its Serbian and Bulgarian allies (in fact, many Muslim peasants fled into Greek-held territory to get away from the other armies, and, especially, from the bands of irregulars which accompanied them), and for the most part it preserved its discipline. When Bosnian Muslims, recently settled by the Young Turks in villages in the plain, greeted the troops in the traditional gesture of surrender by offering them bread and salt, there was no trouble.....
....What stoked tensions and kept them high was the arrival some months after it ended of Greek refugees from Bulgarian and Ottoman Thrace in the east. From late 1913, more than one hundred thousand Greeks suffered ethnic cleansing of their own: they were driven out of their homes by Bulgarian and Ottoman troops and fled westwards. Once safely in Greece, they wanted revenge and took it on local Muslims. Immigrant families occupied Muslim properties and tried to drive out their owners. Others were resettled in Muslim communal buildings. The refugees could often count on the sympathy of Greek gendarmes and denounced Muslim farmers to get them arrested or their homes searched. With no diplomatic representation of their own (at least before the arrival of an Ottoman consul in Salonica in 1914), and no political representation in Greece before the elections of 1915, Muslim grievances and remonstrations fell on deaf ears.....
...Of the 140,000 who had left by April 1914, only 24,000 were from the newly conquered Greek territories: the vast majority had fled the Serbs and Bulgarians, some in anticipation of future troubles, or another war. Nevertheless, the extent of the exodus was reaching the international press, casting a shadow over Greece’s image abroad and jeopardising its relationship with the Ottoman government....
...The Turkish press had their own mirror-image of the Greek allegations: it was all the fault of the Greeks and their purported ‘systematic plan to force the Muslims to emigrate’. Yet this too glossed a more complex reality. The brutality of lower-ranking Greek officials, and the anti-Muslim outlook of many of the men were unmissable. But in the upper echelons of power other considerations were operative. The government was concerned at losing the ‘sober and hardworking’ Muslim farmer through emigration: who would then farm the new lands? No one in Athens dreamed in 1914 that more than one million Greeks might eventually be forced to leave Anatolia. On the contrary, the need to make sure that they were properly treated was a major curb on any officially sanctioned Greek anti-Muslim policy. Junior officers often had to be reminded that every time they drove out a Muslim farmer from Macedonia, there were two more Greek farmers in Anatolia who risked the same fate. The Ottoman government did not bother to hide the link, and there was a clear relationship between the expulsions of Greeks and Turks. Indeed the Turkish authorities began their own deportation of Greek populations from the western coast of Anatolia in the spring of 1914, and were stopped only in a few areas by the protests of powerful beys who feared losing their Christian workforce. The arrival of the Muslim refugees from Macedonia in Anatolia led to the formation of irregular chetté bands which wreaking their revenge on the Christian peasants. In May 1914 40,000 Anatolian Greeks fled the Turkish town of Chesme for the safety of Chios. Not for the first or last time, victims were becoming perpetrators, adding another twist to the spiral of nationalist war...
At the highest levels of the Greek state, however, there was, for all the harassment and persecution, no desire to provoke a large-scale emigration and had it not been for the pressure exerted by incoming Greek refugees, the persecution of Muslims in Greece would have subsided more quickly. As it was, experienced observers in Salonica in spring 1914 were impressed by the extent to which the Greek authorities were trying ‘not to offend the susceptibilities of their Moslem subjects’ and predicted that ‘in time Greek rule may benefit them. In 1915 national elections took place in which Muslims could vote. They were considerably freer than the 1912 elections to the Ottoman parliament had been, and 16 Turkish MPs took their seats in Athens supporting the anti-Venizelist camp. Indeed Salonica’s Muslim (and Jewish) voters became a crucial base of support for Venizelos’s main opponent, something which the Venizelists would neither forgive nor forget, as tempers frayed and the country fell apart during the First World War and its aftermath....