This book is called Philippians because it is addressed to "all the saints in Christ Jesus that are at Philippi" (Philippians 1:1).
The first word in the letter names Paul as the writer. In normal correspondence at that time it was in keeping with good style for the writer to sign his name first.
Internal evidence indicates that Paul wrote the letter about A.D. 63 toward the close of his first imprisonment in Rome (1:12-14; 2:24; 4:32). Some vain attempts have been made to fix it at Corinth, or at Caesarea. Neither place, however, suits the contents.
Philip, King of Macedonia, and father of Alexander the Great, conquered the city from Thrace in 358 B.C., and named it for himself. The Philippi which Paul visited was a Roman colony (Acts 16:12), founded by Augustus Caesar after Augustus and Antony conquered Brutus and Cassius in the famous battle of Philippi, 42 B.C. It is noted in both history and literature, being mentioned prominently in Shakespeare's "Julius Caesar." Located on the East-West trade route, Philippi had great commercial importance. Since the city was a colony of Rome, her citizens enjoyed some special privileges and benefits.
Directed by a vision from God, Paul visited Philippi for the first time on his second mission tour. Lydia and her household were converted. She furnished him a home while he continued his missionary work there. Soon Paul and Silas were beaten and cast into prison. But at midnight they sang and prayed, an earthquake came, they preached the word, and the jailor was converted (Acts 16:13-40). Paul probably visited them again on his third missionary tour while en route from Ephesus to Greece, and on his return spent the Passover there (Acts 20:1-6). The Philippians kept in touch with him, ministering unto his needs (Philippians 4:14-18). The cruel treatment of Paul at Philippi, his reaction to it, and the charm of his personal fervor seemed to knit a bond of profound love between him and the church. Some have called the church Paul's favorite congregation.
The Philippians seem to have been some of the best Christians of the age, and to them Paul directed his most endearing epistle. It contains no rebuke with local bearing, but is filled with tenderness. Love and praise are prominent features. The devotion of the Philippian church caused Paul to rejoice, and since Epaphroditus, who had brought their aid to him, was about to return from Rome to Philippi, the apostle had an opportunity to send them this letter of thanks (Philippians 4:18). The letter should be read often as a spiritual tonic. The key words are love, joy and unity. The object of the epistle seems to be the expression of profound Christian affection. No letter is so warm in its expressions of love.