The capital of the Roman province of MACEDONIA and its largest city — a working port on the Thermaic Gulf, and a stop on the Via Egnatia, the Roman highway running from the Adriatic coast across to Byzantium. Founded about 315 BC by Cassander and named for his wife Thessalonike, a half-sister of Alexander the Great. It was a FREE CITY, governed by its own assembly and magistrates: Luke calls those magistrates politarchai (Acts 17:6), a title once cited as evidence that he had invented his details, until inscriptions bearing it were found in the city itself. ⚠ Paul preached there for at least three sabbaths (Acts 17:1-9), a mob was raised against him in the marketplace, the house of Jason was stormed, Jason was made to post a bond, and the missionaries were sent away by night — so the congregation addressed in this letter was only months old and had been left to face the aftermath without them. Its position explains the letter's boast that the word 'has rung out' from them: a new movement in Thessalonica was news standing on the main road east. The city has been continuously inhabited ever since and is now Greece's second largest.