Thessaloniki is a big, modern city with 1 million inhabitants and the largest urban center of the Prefecture. It was founded in 315 B.C. by the king of Macedonia, Kassandros, son of the general Antipatros who was left as a prefect of Macedonia by Alexander the Great, when he dared his great expedition in Asia.
In this way, Kassandros, having won the battle for succession, married the step-sister of Alexander the Great, Thessaloniki, and founded the city in her honor, uniting 26 small settlements in the vicinity.
In less than two centuries from its establishment, Thessaloniki, just like all of Macedonia, was occupied by the Romans.
In 148 B.C. it was the capital of the Roman province of Macedonia.
A bit later the Macedonian Greeks support the Roman occupation together with whom they face the peoples who often arrived outside of her famous walls trying to gain occupation.
In 42 B.C., Thessaloniki is declared a free city (civitas libera) and begins a new age of peace and prosperity.
Half a century before the birth of Christ, the Roman orator, Cicero, lives in Thessaloniki. The large, famous Egnatia Road for travelers who went from Rome to the East or came back from the West, passes right next to it, uniting the Adriatic to Constantinople. The Roman Empire was finally coming to its end. Two large powers are created with Licinius in the West and Constantine in the East.
Constantine the Great chooses Thessaloniki from where he will engage in his great confrontation with Licinius. He builds the new port of the city and recognizes Christianity as the official religion of the state.
During that period, Thessaloniki acquires important Byzantine churches, many of which visitors will see today during their walks through the city. In the centuries that follow, Thessaloniki suffers from the raids of Goths, Persians, Arabs and Turks without ever losing its character. The city is saved by its great walls of which several of its parts still exist today crowning the city.
In 1185 the Byzantine Empire could not prevent the occupation of Thessaloniki from the Normans. A few years later come the Franks and in 1224 A.D. the city is occupied by Theodoros Doukas Komnenos and is declared the capital of the Bishop of Epirus.
Afterwards, the city will face the threat of the Catalans while from 1300 A.D. enters its golden age. The city experiences a singular autonomy and self-government. It is multi-membered with a strong economy, cultural and artistic life, brilliant monuments, skillfully decorated churches and all sorts of factories: copper, iron, lead, paper etc.
Its cultural renaissance is supported by a series of important orators, theologians, philosophers, lawyers and hagiographers with important works during that period. Grigorios Palamas, Nikolaos Kavasilas, the lawyer Constantine Armenopoulos, Thomas Magistros and the hagiographer Emmanuel Panselinos are all present in Thessaloniki creating their works.
In 1430 A.D., the Ottomans occupy the city and force all those inhabitants that survived the slaughter to abandon the city.
For several years, after the 16th century, the city develops again and its communities of which it is composed live in harmony. Thessaloniki is a populous city, exciting and a cosmopolitan center of the time.
The Greek middle class which gradually formed until the 18th century gave Thessaloniki the glory of the large commercial center.
At the end of the 19th century, Thessaloniki is connected via rail with Skopje and from there with Europe. Also, it is connected with present day Alexandroupolis and Istanbul. The first horse-drawn trams, industries and gas-light are established. Thessaloniki acquires the face of a cosmopolitan, European city. Greeks are now the overwhelming majority of its population.
Liberated Greece in the first years of the 20th century defends its national claims through many sacrifices with the Greek General Embassy of Thessaloniki as its center. However, word of the fall of the Ottoman Empire is evident.
On 26 October, 1912, on the day its protector, St. Dimitrios celebrates, Thessaloniki is liberated by the Greek army and is united to Greece after five centuries of Turkish occupation.
A few years later, after the Asia Minor catastrophe in 1922, and the population exchange with Turkey, Thessaloniki receives the larger part of the refugees, many of whom were of Pontic Greek descent and later comprised significant factors in the economy and social development of the city.