Salonika, or Thessaloniki, was founded in 315 B.C. by Kassandros, king of Macedonia. After the conquest of Macedonian Kingdom by the Romans in 168 B.C., Salonika became the capital city of the Roman "Province of Macedonia".
During the Byzantine era, Salonika was the second most significant city of the Byzantine Empire, after Constantinople. However, In 1442, Salonika revolted against its Byzantine rulers. The "Zelots" defeated their nobles, and created the "Republic of Thessaloniki," a democratic regime autonomous of Byzantium. This short-lived republic lasted only until 1349.
In 1430 A.D., Salonika was conquered by the Turks. 20 years later, The Siege of Constantinople finished the conquering of the Byzantine Empire. This began the Turkish Era in Salonika. The Turks held Salonika until 1912, when the Greeks in the city revolted and took the city.
During World War I, Allied troops arrived and camped in Salonika, in October 1915, thus making the city the center of the "Macedonian Front". In August 1917 a huge fire destroyed almost totally the historical center of the city. An ambitious plan was developed for the reconstruction of Salonika. While never fully completed, it gave the city its modern structure.
Ishobel Ross, diary entry while in Salonika (August 25, 1916)
We can hear the guns more distinctly today, it is such a gruesome sound. We have still had no word of moving. I was in town this afternoon with Woody and Adam. We saw a whole regiment of Italian troops marching up Venizelos Street, Cavalry and Infantry. They looked splendid, and one little man standing besides me, I presume he was an Italian, quite lost his head. He was so excited he jumped up and down as if he were on a spring! The troops were cheered by the crowd that always seemed to gather from nowhere when marching feet were heard. It is extraordinary the number of soldiers of different nationalities that you see in the town.
(Copied and pasted from www.spartacus.schoolnet.co.uk/FWWsalonika)
During World War II, on April 9, 1941, Germany entered Salonika. The German Occupation lasted from April 1941 to October 1944. 45,000 Jewish citizens were transported to concentration camps. Most of them were executed.