Unto Timothy, my own son in the faith:
1 Timothy 1:2
"Paul often sent Timothy to churches as his representative (1 Cor. 4:17; 16:10; Phil. 2:19; 1 Thess. 3:2). And 1 Timothy finds him on another assignment, serving as pastor of the church at Ephesus
The letter claims Paul as its author (1:1), and it is filled with Pauline themes and even contains a brief autobiography (1:11-15). ... acceptance dates as far back as Polycarp, Clement of Rome, Irenaeus, Tertullian, and Clement of Alexandria.
Paul wrote 1 Timothy from Macedonia (in A.D. 62 or 63). He sent the letter to Timothy, whom he had left at Ephesus."