Philippi was a city in Macedonia in the northern province of Greece. It was named for Philip of Macedon, the father of Alexander the Great. It was located on the Egnatian Way, the main east-west highway.
It became a Roman colony in 42 BC, and its inhabitants became citizens. Perhaps many of the residents were soldiers whose service to Rome had been rewarded with land. They were to defend the border and Romanize the surrounding area.
Paul doesn’t mention a synagogue. There were probably very few Jews in the city. There had to be at least 10 Jewish men to start a synagogue. In Philippi, the Jewish women gathered at the river to pray.
Paul’s visits — Acts 16:11-40 and Acts 20:6 — on his second missionary journey.
The church members supported Paul financially (Philippians 4:10-20). Epaphroditus brought the gift to Paul and reported on the church.
Paul wrote the letter while in prison in Rome, around AD 64.
Paul’s epistles are divided into two parts, which helps us to distinguish between his early and latter ministries. The pre-prison epistles of 1 and 2 Thessalonians, 1 and 2 Corinthians, Galatians and Romans were written to the Church, the Body of Christ, in the course of the Acts period. During the apostle’s first Roman imprisonment, which marks the beginning of his latter ministry, he wrote Ephesians, Philippians, Colossians, Philemon and Hebrews. Paul’s letters to Timothy (1 Timothy) and Titus were penned between his two Roman imprisonments when he was set free for a period of about one year (Titus 1:5 cf.3:12; 2 Timothy 4:20). The apostle’s second letter to Timothy was written at the end of his second Roman imprisonment just shortly before his martyrdom. The epistle to the Philippians then was written around 64 AD during the apostle’s first Roman imprisonment. — Paul’s Epistle to the Philippians, by Paul M. Sadler, page 26