The second-largest city of Greece and the principal city of the Greek region of Macedonia, Thessaloniki (also known as Salonika or Salonica) has a population of 1,350,000 including its suburbs, on the Thermaic Bay. It was the capital of one of the four Roman districts of Macedonia, and was ruled by a praetor. It was named after Thessalonica, the wife of Cassander and sister of Alexander the Great, who built the city. She was so called by her father, Philip, because he first heard of her birth on the day of his gaining a victory over the Thessalians.
On his second missionary journey, Paul preached in the synagogue here, the chief synagogue of the Jews in that part of Macedonia, and laid the foundations of a church. Opposition against him from the Jews drove him from the city, and he fled to Berea.
From its capture from Macedonia, Thessaloniki was part of the Roman Empire and Byzantine Empire until Constantinople was captured by the Fourth Crusade in 1204. The city became the capital of the Crusader Kingdom of Thessalonica, until it was captured by the Byzantine state of Epirus in 1224. It was recovered by the Byzantine Empire in 1246, but, unable to hold it against the encroachments of the Ottoman Empire, the Byzantine Despot Andronikos Palaeologus was forced to sell it to Venice, who held it until 1430.
Under the rule of the Ottoman Empire until 1912, the city was known as Salonika and became noted for its majority Jewish population of Sephardic origin, the result mostly of Spain's expulsion of Jews after 1492 (few Romaniotes Jews where also included). The city's language of daily life was Ladino, a Jewish dialect of Spanish. The city's day off was Saturday, the Jewish sabbath.
Salonika was the main prize of the first Balkan war (1912) during which it was liberated by Greece. During World War I a temporary government headed by Eleftherios Venizelos was established there taking the side of the British-French allies, against the will of the pro-neutral German King of Greece. The majority of the town was largely destroyed by a single fire in 1917 of unknown origin, probably an accident. Venizelos forbade the reconstruction of the town centre until a full modern city plan was prepared.
The city gained more population with ethnic Greeks exiled from Smyrna and other areas of modern Turkey in 1922, retaining thus its original national character.
Despite efforts from the Greeks, nearly all of the city's remaining Jews were killed during the German occupation of 1941-1944.
A well-known landmark and symbol of Thessaloniki is the White Tower (Lefkos Pyrgos). Other notable sights include the Arch and Tomb of Galerius, the church of Ayios Dimitrios, and the extensive town walls.