=Paul and Silas at Philippi.= The city of Philippi lay about nine miles northwest of its seaport, Neapolis. It was on the southern side of a great plain that extended to the north and northwest. Its chief river flowed along its eastern side into a huge marsh that flanked the city on the south. Like many of the cities chosen by Paul as the scenes of his labors, it was a Roman colony. It was probably chosen because of its strategic value as one of the outposts of the great empire whose conquest for Christ was already the goal of Paul's endeavor. Also, as the event proved, Rome's protection was of great value to the apostle, who could claim citizenship in the imperial city. Apparently there was only a small Jewish colony at this point and no synagogue, so that Paul established connection with his countrymen at the open place of prayer beside the river and beyond the city walls. The success of their work aroused the inevitable opposition and led to their imprisonment; but on this occasion they were sent forth from the city at the request of the magistrates rather than by force. =At Thessalonica.= From Philippi they proceeded westward along the well-travelled Egnatian Way to Thessalonica, the capital and chief commercial city of Macedonia. It lay at the northeastern end of the Thermaic Gulf, the present Gulf of Salonica, in a great ampitheatre formed by the surrounding hills, which were crowned by a strong citadel. Vast plains lay behind the city and it commanded the trade of the northern Ægean. Because of its loyalty to the cause of Octavius and Antony it had been made a free city, ruled by its own assembly and magistrates, called Politarchs. Here, as at Philippi, Paul succeeded in laying the foundations of a strong Christian church, composed largely of the Greek converts to Judaism. The hostile Jews soon charged Paul and Silas with stirring up sedition and rebellion, a charge to which the rulers of a free city like Thessalonica were especially ready to listen. Much to his regret, Paul was therefore obliged suddenly to leave the city. =Paul at Berœa.= As in his flight from Iconium, he now found refuge at a quiet, retired town. Berœa lay fifty miles southwest of Thessalonica, in the midst of groves of trees and flowing streams. It was flanked by a bold mountain range on the west and faced toward the Ægean, with a broad expanse of plain lying in the foreground. Here Paul found a nobler type of Jews, probably untouched by the mercenary spirit of those who had been attracted to the great commercial centres like Thessalonica and Philippi. His work among both the Jews and Greeks was very successful until emissaries came from Thessalonica. Paul's heart was evidently set upon returning to take up his work at the Macedonian metropolis, but events had proved that this was impossible.