St. Afra of Sirmium was a Christian martyr who lived during the 3rd century in what is now modern-day Serbia. She is known for her steadfast faith in the face of persecution, ultimately leading to her execution. St. Afra is often associated with the early Christian community in Sirmium, which was a significant center for Christianity during that time. Her feast day is celebrated on September 7, and she is venerated in both the Roman Catholic and Eastern Orthodox traditions. St. Afra is considered a symbol of courage and devotion, inspiring many believers to remain faithful despite challenges.