The term "captivity epistles" has been applied to four letters traditionally attributed to Paul: Philippians, Philemon, Ephesians, and Colossians. Though each of these letters is claimed to be by Paul, and each makes reference to his imprisonment, in fact it seems the designation "captivity epistles" was always a "leftover" category, the other groups consisting of the great epistles (Rom, Gal 1 and 2 Cor), the pastorals, and the Thessalonian correspondence. In fact, 2 Timothy has several references to Paul's imprisonment (2 Tm 1:16–17, 2:9, 4:16–17), and yet its themes and vocabulary have placed it in the category of the pastorals.
On the basis of themes and vocabulary, Philippians and Philemon fit well together, as do Ephesians and Colossians, but the four taken together are not so homogeneous. For Philippians and Philemon, the place of imprisonment is not certain. Four possibilities have been suggested for Philippians: Corinth, Rome, Caesarea, and Ephesus, with the latter three also possibilities for Philemon.
Most contemporary scholars do not accept Paul as the author of Ephesians and Colossians, although in his recent commentary J. D. G. Dunn takes the position that Colossians most likely comes from a hand other than Paul's, but that it was written around the same time as Philemon, possibly with Paul's knowledge and approval. In his monograph on the disputed Paulines, Raymond F. Collins points out that a number of scholars find indications that Colossians was used as a source for Ephesians.
Bibliography: m. bockmuehl, The Epistle to the Philippians (Black's New Testament Commentary 11; London 1998). r. f. collins, Letters That Paul Did Not Write (Good News Studies 28; Wilmington 1988). j. d. g. dunn, The Epistles to the Colossians and to Philemon (Grand Rapids, Mich. 1996). m. y. macdonald, Colossians and Ephesians (Sacra Pagina 17; Collegeville, Minn.2000).
"Captivity Epistles." New Catholic Encyclopedia. . Encyclopedia.com. (August 17, 2018). http://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/captivity-epistles
"Captivity Epistles." New Catholic Encyclopedia. . Retrieved August 17, 2018 from Encyclopedia.com: http://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/captivity-epistles