Galatians and Acts both describe a meeting in Jerusalem that settled, at least in principle, whether Gentile converts needed to be circumcised, but the two accounts do not align easily, and reconciling them is one of the oldest problems in New Testament chronology. Whether Galatians was written before or after that council, and whether "Galatia" names the ethnic region evangelized later in Paul's career or the Roman province in the south that Paul passed through earlier, changes the letter's date by several years and remains a genuinely unresolved scholarly question, the North Galatia and South Galatia hypotheses, argued on both sides without full agreement.
What is not in dispute is the letter's consequence: its argument that Gentile believers were not obligated to Jewish law became, through Paul's wider mission and eventually through Acts 15's ruling, the settled position of the church that has come down to the present, and the theological principle at its center, justification by faith apart from law observance, became, alongside Romans, the central proof text of the Protestant Reformation. Galatians is also the primary source for what little is known of Paul's biography in his own words, since it is here, not in Acts, that he insists his gospel came to him "not from any human source" but by direct revelation.