St. Euphemia is a Christian martyr who lived during the early centuries of the Church. She is often celebrated for her steadfast faith and courage in the face of persecution. Her feast day is observed on September 16, and she is venerated in various Christian traditions, particularly within the Eastern Orthodox and Roman Catholic churches. The most famous relic associated with St. Euphemia is her body, which is believed to be housed in the Church of St. Euphemia in Chalcis, Greece. This church has become a pilgrimage site for many believers seeking her intercession and honoring her legacy as a symbol of faith and resilience.