Onesimus was a first-century Christian who is famously featured in the New Testament, specifically within the Epistle to Philemon. Originally a slave belonging to a man named Philemon, he fled and eventually encountered the Apostle Paul while the latter was imprisoned. After converting to Christianity through Paul's teachings, he was reconciled with his former master. Depending on historical and ecclesiastical traditions, he is identified as a bishop, potentially serving in Ephesus or as a leader in Byzantium.