A. Philemon, Colossians, Ephesians 

1. Ephesians and Colossians have strong interrelationship 
Of 155 verses in Ephesians, 73 have verbal parallels in Colossians. 
Only brief portions of Ephesians have no parallels in Colossians, i.e., 2:6-9; 4:4-13; 5:29-33 et al. 
2. Tychicus is a connecting link for all three. 
Eph. 6:21-22: he is being sent to Ephesus with Ephesians. 
Col. 4:7-9: he is being sent to Colossae with Colossians. 
Col. 4:9: He was accompanied by Onesiumus in Philemon. 

C. The issue of where Paul was when these four letters were written, assuming Pauline authorship. 

1. Rome (imprisonment in 61-62 AD) for all four letters. 
Traditional view. 
Eph. Col. Philm would have been in early part of that period 
Phil. would have been toward close of that period. 
2. Caesarea (imprisonment in 58-59 AD). 
First adopted by H.E.G. Paulus in 1799. 
A currently popular alternative to traditional view above 
3. Ephesus (imprisonment in mid 50s, mentioned in 1 Cor. 15:32; 2 Cor. 11:23; 6:5; 1:8; 1 Clement 5:6) 
First adopted by Adolf von Deissmann in 1897. 
Referred to in the Marconite Prologue to Colossians 
Adopted by some contemporary New Testament scholars, especially for Philippians.