People often wonder: “What is the true story of St. Patrick’s Day?” The holiday is named after St. Patrick, a Patron Saint of Ireland, who died around the fifth century. However, St. Patrick is thought to have been a Roman citizen in Britain who was enslaved and taken to Ireland, either escaped or was released, then returned as a priest and converted Druids to Christianity, Marion Casey, a clinical assistant professor of Irish Studies at New York University, previously told TIME.