The city was founded around 315 BC by the King Cassander of Macedon, on or near the site of the ancient town of Therma and twenty-six other local villages. He named it after his wife Thessalonike, a half-sister of Alexander the Great. She gained her name (“victory of Thessalians”: Gk nikē “victory”) from her father, Philip II, to commemorate her birth on the day of his gaining a victory over the Phocians, who were defeated with the help of Thessalian horsemen, the best in Greece at that time. Thessaloniki developed rapidly and as early as the 2nd century BC the first walls were built, forming a large square. It was an autonomous part of the Kingdom of Macedon, with its own parliament where the King was represented and could interfere in the city’s domestic affairs.

After the fall of the kingdom of Macedon in 168 BC, Thessalonica became a city of the Roman Republic. It grew to be an important trade-hub located on the Via Egnatia, the Roman road connecting Byzantium (later Constantinople), with Dyrrhachium (now Durrës in Albania), and facilitating trade between Europe and Asia. The city became the capital of one of the four Roman districts of Macedonia; it kept its privileges but was ruled by a praetor and had a Roman garrison, while for a short time in the 1st century BC, all the Greek provinces came under Thessalonica (the Latin form of the name). Due to the city’s key commercial importance, a spacious harbour was built by the Romans, the famous Burrowed Harbour (Σκαπτός Λιμήν) that accommodated the town’s trade up to the eighteenth century; later, with the help of silt deposits from the river Axios, it was reclaimed as land and the port built beyond it. Remnants of the old harbour’s docks can be found in the present day under Odos Frangon Street, near the Catholic Church.

Thessaloniki’s acropolis, located in the northern hills, was built in 55 BC after Thracian raids in the city’s outskirts, for security reasons.

The city had a Jewish colony, established during the first century, and was to be an early centre of Christianity. On his second missionary journey, Paul of Tarsus, born a Hellenized Israelite, preached in the city’s synagogue, the chief synagogue of the Jews in that part of Thessaloniki, and laid the foundations of a church. Other Jews opposed to Paul drove him from the city, and he fled to Veroia. Paul wrote two of his epistles to the Christian community at Thessalonica, the First Epistle to the Thessalonians and the Second Epistle to the Thessalonians.

Thessaloníki acquired a patron saint, St. Demetrius, in 306. He is credited with a number of miracles that saved the city, and was the Roman Proconsul of Greece under the anti-Christian emperor Maximian, later martyred at a Roman prison where today lies the Church of St. Demetrius, first built by the Roman sub-prefect of Illyricum Leontios in 463. Other important remains from this period include the Arch and Tomb of Galerius, located near the centre of the modern city.

When in 379 the Roman Prefecture of Illyricum was divided between East and West Roman Empires, Thessaloniki became the capital of the new Prefecture of Illyricum (now reduced in size). Its importance was second only to Constantinople itself, and in 390 it was the location of a revolt against the emperor Theodosius I and his Gothic mercenaries. Botheric, their general, together with several of his high officials, were killed in an uprising triggered by the imprisoning of a favorite local charioteer for pederasty with one of Botheric’s slave boys. 7,000 – 15,000 of the citizens were massacred in the city’s hippodrome in revenge – an act which earned Theodosius a temporary excommunication.

A quiet interlude followed until repeated barbarian invasions after the fall of the Roman Empire, while a catastrophic earthquake severely damaged the city in 620 resulting in the destruction of the Roman Forum and several other public buildings. Thessaloniki itself came under attack from Slavs in the seventh century; however, they failed to capture the city. Byzantine brothers Saint Cyril and Saint Methodius were born in Thessaloniki and the Byzantine Emperor Michael III encouraged them to visit the northern regions as missionaries; they adopted the South Slavonic speech as the basis for the Old Church Slavonic language. In the ninth century, the Byzantines decided to move the market for Bulgarian goods from Constantinople to Thessaloniki. Tsar Simeon I of Bulgaria subsequently invaded Thrace, defeated a Byzantine army and forced the empire to move the market back to Constantinople. In 904, Saracens, led by Leo of Tripoli, managed to seize the city and after a ten day depredation, left, with much loot and 22,000 slaves, mostly young people.

The city recovered, and the gradual restoration of Byzantine power during the tenth, eleventh and twelfth centuries brought peace to the area. The population of the city expanded, and according to Benjamin of Tudela, the city also had a Jewish community some 500-strong by the twelfth century. It also hosted the fair of Saint Demetrius every October, which was held just outside the city walls and lasted six days.

The economic expansion of the city continued through the twelfth century as the rule of the Komnenoi emperors expanded Byzantine control into Serbia and Hungary, to the north. The city is known to have housed an imperial mint at this time. However, after the death of the emperor Manuel I Komnenos in 1180, the fortunes of the Byzantine Empire began to decline, and in 1185 the Norman rulers of Sicily, under the leadership of Count Baldwin and Riccardo d’Acerra, attacked and occupied the city, resulting in considerable destruction. Nonetheless, their rule lasted less than a year, and they were defeated by the Byzantine army in two battles months later and forced to evacuate the city.

Thessaloniki passed out of Byzantine hands in 1204, when Constantinople was captured by the Fourth Crusade. Thessaloniki and its surrounding territory — the Kingdom of Thessalonica — became the largest fief of the Latin Empire, covering most of north and central Greece, and was given by the emperor Baldwin I to his rival Boniface of Montferrat, but seized back once more in 1224 by Theodore Komnenos Doukas, the Greek ruler of Epirus. In 1235, Tsar Ivan Asen II of Bulgaria subjugated the Despotate of Epirus and made the rulers of Thessaloniki his vassals. The city was recovered by the Byzantine Empire in 1246.

At this time, despite intermittent invasion, Thessaloniki sustained a large population and flourishing commerce, resulting in intellectual and artistic endeavour that can be traced in the numerous churches and frescoes of the era, and by the evidence of its scholars teaching there. Examples of Byzantine art survive in the city, particularly the mosaics in some of its historic churches, including the basilica of Hagia Sophia of Thessalonki, and the church of St George.

In the 14th century, however, the city faced upheaval in the form of the Zealot social movement (1342-1349), springing from a religious conflict between bishop Gregorios Palamas, who supported conservative principles, and the monk Barlaam, who introduced progressive social concepts. Quickly, it turned into a political commotion, leading to the preeminence of the Zealots, who ruled the city for a time and applied progressive social ideas.

The Byzantine Empire, unable to hold the city against the Ottoman Empire’s advance, sold it in 1423 to Venice. Venice held the city until it was captured after a three-day-long siege by the Ottoman Sultan Murad II on 29 March 1430. The Ottomans had previously captured Thessaloniki in 1387, but lost it in the aftermath of their defeat in the Battle of Ankara against Tamerlane in 1402, when the weakened Ottomans were forced to hand back a number of territories to the Byzantines.

During the Ottoman period, the city’s Muslim and Jewish population grew. By 1478, Thessaloniki had a population of 4,320 Muslims and 6,094 Greek Orthodox, as well as some Catholics, but no Jews. By ca. 1500, the numbers had grown to 7,986 Greeks and 8,575 Muslims, briefly making the latter the majority. Around the same time, Jews began arriving from Spain, fleeing persecution. In ca. 1500, there were only 3,770 Jews, but by 1519, there were 15,715, 54% of the city’s population. The invitation of the Sephardic Jews expelled from Spain by Ferdinand and Isabella, was an Ottoman demographic strategy aiming to prevent the Greek element from dominating the city. The Sephardic Jews, Muslims and Greek Orthodox remained the principal groups in the city for the next 4 centuries.

The city remained the largest Jewish city in the world for at least two centuries, often called “Mother of Israel”. Of its 130,000 inhabitants at the start of the 20th century, around 60,000 were Sephardic Jews. Some Romaniote Jews were also present.

Thessaloníki, called Selânik in Turkish, became one of the most important cities in the Empire, viable as the foremost trade and commercial center in the Balkans. The railway reached the city in 1888 and new modern port facilities were built in 1896-1904. The founder of modern Turkey, Mustafa Kemal Atatürk, was born there in 1881, and the Young Turk movement was headquartered there in the early twentieth century.

Selânik was a sanjak center in the Rumeli eyalet from 1393 to 1402 and again from 1430 to 1864, when it became a vilayet (province). The Ottoman vilayet of Selânik province included the sanjaks of Selânik (Thessaloniki), Drama, and Serres (Siroz or Serez).

Architectural remains from the Ottoman period can be found mainly in the Ano Poli (Upper Town) which has the only traditional wooden houses and fountains to survive the city’s fire. In the city center, a number of the stone mosques survived, notably the “Hamza-Bey Camii” on Egnatia (under restoration), the “Alatza Imaret Camii” on Kassandrou Street, “Bezesteni” on Venizelou Street, and “Yahoudi Hamam” on Frangon Street. Most of the more than 40 minarets were demolished after 1912, or collapsed because of the fire; the only surviving one is at the Rotonda (Arch and Tomb of Galerius). There are also a few remaining Ottoman hammams (bathhouses), particularly the “Hamam Bey” on Egnatia Avenue.

From 1870, driven by economic growth, the city’s population exploded by 70%, reaching 135,000 in 1917.

During 19th century, Thessaloníki became one of the cultural and political centres of the Bulgarian revival movement in Macedonia. According to Bulgarian ethnographer Vasil Kanchov around the beginning of the 20th century there were approximately 10,000 Bulgarians, a substantial minority in the city. In 1880 a Bulgarian Men’s High School was founded, followed later by other educational institutions of the Bulgarian Exarchate. In 1893 a part of the Bulgarian intelligentsia created a revolutionary organization, which spread its influence among Bulgarians throughout Ottoman Balkans and became the strongest Bulgarian paramilitary movement, best known under its latest name, the Internal Macedonian Revolutionary Organization (IMRO). In 1903 a group of Bulgarian leftists and anarchists, tied to IMRO, organized series of Thessaloniki bombings of 1903. After the Young Turk Revolution of 1908, Thessaloniki became a centre of Bulgarian political activity in the Ottoman Empire and seat of the two largest legal Bulgarian parties, the rightist Union of the Bulgarian Constitutional Clubs, and the leftist People’s Federative Party (Bulgarian Section).

During the First Balkan War, the Ottoman garrison surrendered Salonika to the Greek Army, on 9 November 1912. This was a day after the feast of the city’s patron saint, Saint Demetrios, which has become the date customarily celebrated as the anniversary of the city’s liberation. The next day, a Bulgarian division arrived, and Bulgarian troops were allowed to enter the city in limited numbers. Although officially governed by the Greeks, the final fate of the city hung in the balance. The Austrian government proposed to make Salonika into a neutral, internationalized city similar to what Danzig was to later become; it would have had a territory of 400-460 km² and a population of 260,000. It would be “neither Greek, Bulgarian nor Turkish, but Jewish”.

The Greeks’ emotional commitment to the city was increased when King George I of Greece, who had settled there to emphasize Greece’s possession of it, was assassinated on 18 March 1913 by Alexandros Schinas. After the Greek and Serbian victory in the Second Balkan War, which broke out among the former allies over the final territorial dispositions, the city’s status was finally settled by the Treaty of Bucharest on August 10, 1913, becoming an integral part of Greece. In 1915, during World War I, a large Allied expeditionary force landed at Thessaloniki to use the city as the base for a massive offensive against pro-German Bulgaria. This precipitated the political conflict between the pro-Allied Prime Minister, Eleftherios Venizelos, and the pro-neutral King Constantine. In 1916, pro-Venizelist army officers, with the support of the Allies, launched the Movement of National Defence, which resulted in the establishment of a pro-Allied temporary government, headed by Venizelos, that controlled northern Greece and the Aegean, against the official government of the King in Athens. Ever since, Thessaloniki has been dubbed as symprotévousa (“co-capital”).

Most of the old town was destroyed by a single fire on 18 August 1917, accidentally sparked by French soldiers in encampments at the city. The fire left some 72,000 homeless, many of them Turkish, of a population of approximately 271,157 at the time. Venizelos forbade the reconstruction of the town center until a full modern city plan was prepared. This was accomplished a few years later by the French architect and archeologist Ernest Hebrard. The Hebrard plan, although never fully completed, swept away the oriental features of Thessaloníki and transformed it into the modern European metropolis that it is today. One effect of the great fire was that nearly half of the city’s Jewish homes and livelihoods were destroyed, leading to massive Jewish emigration. Many went to Palestine, others to Paris, and still others found their way to the United States. Their populations, however, were quickly replaced by considerable numbers of refugees from Asia Minor as a result of the population exchange between Greece and Turkey, following the defeat of the Greek forces in Anatolia during the Greco-Turkish War. With the arrival of these new refugees, the city expanded enormously and haphazardly, and came to be nicknamed “The Refugee Capital” (I Protévousa ton Prosfýgon) and “Mother of the Poor” (Ftokhomána).

hessaloniki fell to the forces of Nazi Germany on April 22, 1941, and remained under German occupation until 30 October, 1944. The city suffered considerable damage from Allied bombing, and almost its entire Jewish population was exterminated by the Nazis. Barely a thousand Jews survived. Thessaloniki was rebuilt and recovered fairly quickly after the war, with this resurgence taking in both a rapid growth in its population, and a large-scale development of new infrastructure and industry throughout the 1950s, 1960s and 1970s. Most of the urban development of that period was, however, without an all-embracing plan, contributing to the traffic and zoning problems remaining to this day.

On 20 June, 1978, the city was hit by a powerful earthquake, registering a moment magnitude of 6.5. The tremor caused considerable damage to several buildings and even to some of the city’s Byzantine monuments; forty people were crushed to death when an entire apartment block collapsed in the central Hippodromio district. Nonetheless, the large city recovered with considerable speed from the effects of the disaster. Early Christian and Byzantine monuments of Thessaloniki were inscribed on the UNESCO World Heritage list in 1988, and Thessaloniki later became European City of Culture 1997.

Thessaloniki is one of the most important university centres in the Southeastern European region, and is also host to a student population from across Greece. The city sustains two state universities — the Aristotle University of Thessaloniki, the largest university in Greece (founded 1926), and the University of Macedonia, alongside the Technological Education Institute of Thessaloniki. It also sponsors a range of private international institutions, either affiliated with universities in other nations, or accredited abroad.

In June 2003, the Summit meeting of European leaders, at the end of the Greek Presidency of the EU, was hosted at the Porto Carras resort in Chalkidiki, instead of within the Thessaloniki city limits themselves, to aid security precautions, and in 2004 the city hosted a number of the football events forming part of the 2004 Summer Olympics. Thessaloniki unsuccessfully bid for the 2008 World EXPO, this time won by Zaragoza in Spain, but another planned bid for 2017 was announced in September 2006 and is now in full development.