This is the name of 2 biblical cities.
Philippi, the capital of the province of Macedonia
formerly Crenides—“the fountain”
This city was miles inland from the Mediterranen seaport of Neapolis (now Kavala, Greece). Philip of Macedonia fortified the old Thracian town of Crenides, and called it after his own name Philippi (359-336 B.C.).
Having been providentially guided to Philippi, Paul and his companion Silas preached the Gospel here and formed the first church in Europe. This success stirred up the enmity of the people, and they were “shamefully entreated” (Acts 16:9-40; 1 Thess. 2:2). Paul and Silas at length left this city and proceeded to Amphipolis.
When Philip the tetrarch, the son of Herod, succeeded to the government of the northern portion of his kingdom, he enlarged the city of Paneas (a place dedicated to the worship of Greek god Pan), and called it Caesarea, in honor of the emperor. But in order to distinguish it from the Caesarea on the sea coast, he added to it subsequently his own name, and called it Caesarea-Philippi.