Thessaloniki is the second largest city in Greece. It is the seat of the municipality of the same name, the Regional Unity of Thessaloniki, the Region of Central Macedonia and the Decentralized Administration of Macedonia - Thrace. Since its foundation by Kassandros, Thessaloniki as a thriving Hellenistic city until Ottoman domination has capitalized on its strategic position and is being developed into a multicultural city. Since 1912, with the end of the Balkan Wars and the incorporation of the area into the modern Greek state, Thessaloniki is the second largest city in Greece. It is often referred to as the co-capital of Greece.
The population of the urban complex is now estimated at 788.191 inhabitants (Census 2011), while the population of the metropolitan center is 1. 450.000 inhabitants .
The founding of the city in the Hellenistic era coincided with a critical phase in the history of the Macedonian Kingdom, beginning with the early death of Alexander the Great and the claim of the throne of the Macedonian king by his descendants. General Cassander, in order to be able to claim the throne of Macedonia, married the half-sister of Alexander the Great, Thessaloniki, in honor of which he founded the city, uniting 26 villages around the Thermaic Gulf.
In the 2nd century BC the city was conquered by the Romans, like the rest of Greece, and was the seat of the Roman theme of Macedonia. The strategic position of the city first emerged when it was selected as an imperial capital during the reign of Galerius when the imperial palace was built.
Its significance was apparent later on by the intention of transferring the capital of the Roman Empire from Megalo Constantine to the east, as it was one of the candidate cities that had been proposed as replacements of Rome, to eventually choose Byzantium. In spite of its non-selection as a capital, it acquires the title of the city council during the Byzantine period.
After its Ottoman conquest by the Ottomans in 1432, it remained in the Ottoman Empire for about five centuries. With the expulsion of the Jews from the Iberian peninsula and northern Europe, Thessaloniki acquires its own Jewish community.
This Jewish establishment in Thessaloniki has made the city the most important Jewish metropolis worldwide until at least the early 20th century. Particularly since the middle of the 19th century, the city has been the most cosmopolitan urbanization center of the Ottoman Empire and the most important pole of political movements and movements that has met in its long history.
With its accession to the Greek State's torso in 1912, the city's population is undergoing significant changes with the movement of the Muslim population and its replacement by refugee populations in Asia Minor and East Thrace.
The population changes contributed to the change of the population situation of the city with the strengthening of the Greek element. Its urban and architectural reorganization was accelerated by the Great Fire of 1917 and the efforts of the new Greek administration to add ancient Greek and European elements to the architectural style of the city, which led to the destruction of several Ottoman cult and functional buildings.
The most significant population changes have been observed with the installation of the Asia Minor and Thracian refugee population following the Asia Minor Disaster in 1922, with the Holocaust of the racial Jewish community by the Nazi troops during the triple occupation during the Second World War and the internal migration is observed in the 1950s and later to large urban centers.