Thessalonica in Wikipedia
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 Durres 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.