Thessaloniki was within the Ottoman Empire until 1912 with the name of Salonika, mostly inhabited by Jews. After the Second Balkan War, the Bucharest Treaty was signed, according to which Thessaloniki was handed over to Greece and renamed Thessaloniki. Tens of thousands of Bulgarians are ousted forever from their native places. The Bulgarian School of Gymnasium of Thessaloniki is closed, as well as the girls’ high school, the Bulgarian church “St. St. Cyril and Methodius “, the Bulgarian Church, the Exarchate Board of Trustees and many other Bulgarian cultural institutions. There have been recorded repressions by Greek soldiers against Bulgarians, Jews and Turks, resulting in armed clashes with Bulgarian parts.
On March 5, 1913, the Greek King George I of Greek anarchist was killed in Thessaloniki.
During the First World War, Thessaloniki was occupied by Anglo-French troops and became the main base in their war against Bulgaria and its allies. In the city under their patronage, a temporary Greek government, headed by Eleftherios Venizelos, which is on the side of the French-British allied forces, despite the guardian neutrality of King Konstantinos I.
In the great fire of 1917, most of the city was destroyed. This forces the mass of the Jewish population who lost their property in the fire to emigrate. Most of them go to Palestine, France and the United States. The population of the city grew rapidly after the 1922 war between Greece and Turkey and the subsequent Asia Minor catastrophe. The Greeks are broken down by the Turkish army under Ankara and are losing the Aztecs coast of Asia Minor with the city of Izmir. Thousands of refugees from these areas have settled in Thessaloniki, bringing their customs and traditions. This has a major impact on the further development of the city and among the expulsion of many local ethnic Bulgarians substantially amended its stock in favor of the Greeks. The new Thessaloniki Urban Plan was drafted on the order of Ev. Venizelos by architect Ernesto Ebrar. In 1926, a new fire burned the Jewish quarter of Colombo.