Bithynia was a Roman province located in the northwest corner of Asia Minor. The apostle Paul and Silas wanted to preach the gospel in Bithynia on Paul’s second missionary journey but were prevented by the Holy Spirit from doing so (Acts 16:7). The apostle Peter may have ministered in Bithynia and other provinces of Asia Minor, since he addressed his first letter to believers there (1 Pt 1:1). Christianity entered Bithynia somehow, possibly through Peter.
Bithynia was occupied by a Thracian tribe that established a prosperous kingdom there in the third century bc. In 75 bc, when Bithynia’s last king, Nicomedes III, willed his kingdom to the Roman people, it became part of the Roman Empire. For administrative purposes, it was generally linked with the province of Pontus to the east.
After NT times, Bithynia figured significantly in church history. Early in the second century, its Roman governor, Pliny the Younger, elicited from the emperor Trajan the earliest stated imperial policy on persecution of Christians. Later, the church councils of Nicaea (ad 325) and Chalcedon (451) were held in two of Bithynia’s western cities. The Council of Nicaea declared the full deity of Christ; the Council of Chalcedon made pronouncements on the nature of the person of Christ and the canonicity of the 27 NT books.
The Roman province of Bithynia was bordered on the north by the Black Sea, on the west by the Propontis (modern Sea of Marmara), on the south by the province of Asia, and on the east by Galatia and Pontus. Bithynia was mountainous, with Mt Olympus in the south rising to 7,600 feet (2,315.5 meters), but had districts of great fertility near the seacoast and in its interior valleys. Besides producing fruit and grain, the province had fine marble quarries, good timber, and excellent pasturage. The principal river was the Sangarius (modern Sakarya), which flowed from south to north into the Black Sea. Transportation was largely along the river valleys.1
Elwell, W. A., & Comfort, P. W. (2001). Tyndale Bible dictionary. Tyndale reference library (224–225). Wheaton, Ill.: Tyndale House Publishers.↩