Outside this letter there is no mention in the New Testament of the city of Colossae, and from the letter itself it is clear that Paul had never been there. The church had been founded by an assistant of Paul's named Epaphras, who appears to have been a native of the city; and to the question when this happened the most likely answer can be found in the account in Acts of Paul's stay in Ephesus. His work there “continued for two years, so that all the residents of Asia, both Jews and Greeks, heard the word of the Lord” (19.10). Colossae, with Laodicea and Hierapolis, made up a group of three small cities some 100 miles inland from Ephesus, in the valley of the river Lycus. Christian communities had taken root in all three of them (4.13), and the obvious time for this to have taken place is during Paul's activity in Ephesus.

From the last sentence in the letter it appears that Paul was writing in prison, and it has generally been assumed that the imprisonment referred to is that which Paul underwent while awaiting trial in Rome. As with Philippians (which was also written from prison), there are reasons for doubting this: Rome was too far away from Asia for some of the contacts mentioned in these letters to have been maintained, and Paul himself mentions other ‘imprisonments’ (2 Corinthians 11.23) – there may well have been one at Ephesus (1 Corinthians 15.32).