The Romans made Galatia part of the Roman Empire in 121 B.C. The province of Galatia contained a number of regions. The northern region was known as Galatia proper and the southern region included Pisidia, Phyrgia, and Lycaonia.
The majority of the people in Galatia spoke the language of their particular city, even though Latin and Greek were the official languages during Roman rule. Most individuals also continued to practice the religion particular to their culture. Often the people renamed their deities, calling them by the name of the Greek or Roman gods while maintaining the distinction of the original deities.
During Paul's first missionary journey he evangelized in Pisidian Antioch, Iconium, Lystra, and Derbe, which are all cities in the region of Galatia. When Paul wrote his Epistle to the Galatians, it is most likely that he was addressing it to all of the churches he had established in the province.
The province of Galatia consisted of various ethnic groups, including Jews, though it was predominantly Gentile. Some of the cities of this region had powerful Jewish bodies.