An old city, rich in history, Thessaloníki was founded (c.315 B.C.) by Cassander, king of Macedon, on or near the site of the ancient town of Therma, and was named for his wife. The city was located on the Via Egnatia, an important Roman road that linked Byzantium to Durrës (Dyrrhachium) on the Adriatic. It flourished after 146 B.C. as the capital of the Roman province of Macedon. Thessaloníki had from early times a sizable Jewish colony, and it was an early Christian diocese. To the infant church there, St. Paul addressed his two epistles to the Thessalonians.
Under the Byzantine Empire Thessaloníki was second only to Constantinople. The massacre (A.D. 390) of the rebellious citizens of Thessaloníki by order of Theodosius I led to the emperor's temporary excommunication. The city was occupied by the Saracens in 904 and by the Normans of Sicily in 1185. When in 1204 the leaders of the Fourth Crusade created a Latin empire (see Constantinople, Latin Empire of), the kingdom of Thessaloníki, comprising most of N and central Greece, was its largest fief. It was given by Baldwin I to his rival Boniface, marquis of Montferrat, but it was seized (c.1222) by the Greek ruler of Epirus, who had himself proclaimed emperor.
The kingdom of Thessaloníki fell into anarchy in the struggle between the Greek rulers of Epirus and the Greek emperors of Nicaea. In 1246 the city fell to the Nicaeans, who in 1261 restored it to the Byzantine Empire. Thessaloníki was conquered by the Ottoman Sultan Murad I in 1387, was restored to the Byzantine Empire c.1405, was bought by Venice in 1423, and was reconquered by the Ottoman Turks (under Murad II) in 1430. Thessaloníki remained in Ottoman hands until it was conquered by Greece in 1912 during the Balkan Wars. The city was the birthplace of Kemal Atatürk, the founder of modern Turkey, and was the headquarters of the Young Turk movement in the early 20th cent.
In World War I the Allies landed (1915) at Thessaloníki, thus beginning the Thessaloníki campaigns, and in 1916 Venizelos established his pro-Allied provisional government of Greece there. A great fire in 1917 destroyed much of the city. Thessaloníki suffered considerable damage in World War II, and its large (c.50,000) Jewish population, which had been greatly increased in the late 15th and early 16th cent. by an influx of Jews from Spain, was nearly liquidated by the Germans. In 1978 an earthquake destroyed part of the city.