It is a Roman Catholic cathedral, famous for holding the relics of St. Thomas The Apostle. The relics were brought in 1258 from the Island of Chios (in the Aegean Sea) to Ortona by the sailor Leone Acciaiuoli. Originally built in the 9th century, the cathedral was destroyed by the Normans and then rebuilt in the 11th century. Nowadays, the Basilica still preserves the original stone portals and a baroque inner dome.