The Skulls of Otranto Cathedral: Who the 813 Martyrs Were and What Happened in 1480

Otranto is a town in Apulia, in southern Italy. In 1480 it became a target in the westward expansion of the Ottoman Empire under Sultan Mehmed II. The force that came ashore was commanded by Gedik Ahmed Pasha. According to the Archdiocese of Otranto, the city then had about 6,000 inhabitants, and the Ottoman force arrived with approximately 150 ships and 15,000 men (Archdiocese of Otranto).

So, did the Ottoman Empire really conquer a city in southern Italy? Yes. Otranto fell in August 1480, after a siege. Antonio Primaldo and hundreds of other inhabitants of the city were then put to death near the Hill of Minerva, close to the city. The Archdiocese gives the number of those killed as 813, and it is that tradition that gives the martyrs their best-known name.

The city did not stay in Ottoman hands. Otranto was liberated in 1481, and the Archdiocese dates the next part of the martyrs' story to that year.

The events at Otranto are told in two ways, and both matter to anyone trying to understand the skulls in the chapel.

The first is the Church's account. In the diocesan tradition, the 813 inhabitants of Otranto were told to renounce their Christian faith, refused, and were executed for it. Pope Francis, in his homily at their canonization, described them as about 800 people who had survived the siege and invasion of Otranto and were beheaded near the city after refusing to deny their faith (Vatican homily). For Catholics, that refusal is the heart of why they are honored as martyrs and saints.

The second is the historians' discussion of the written record. The historian Roberto Mondola, in a 2014 study, traces how accounts of the capture and the martyrdom grew through a series of later Italian and Spanish historical works, many of them explicitly apologetic, that is, written to defend a religious position (Mondola, 2014). Konstantinos Giakoumis, studying the Ottoman campaign to Otranto and Apulia in 1480 and 1481, notes that estimates of the Ottoman force differ and that contemporary accounts disagree about the scale and sequence of the fighting (Giakoumis).

Put side by side, the two accounts agree on the core: Otranto was captured in 1480, and a large number of its people were executed outside the city. The exact figure of 813 and the details of the demand that they convert come down to us through the devotional tradition, and they are best given as that tradition gives them. Holding both accounts together doubts no one's faith; it is how the story of Otranto is told by those who study it, inside the Church and outside it.

The Archdiocese records that the bodies of the dead remained where they fell for about a year. In June 1481, after Otranto was liberated, they were placed in a nearby church known as "al fonte della Minerva," near the Hill of Minerva. On 13 October 1481 they were carried into Otranto Cathedral (Archdiocese of Otranto).

Not all of them stayed. Alfonso of Aragon had many of the remains taken to Naples. The Archdiocese's general history dates this to 1490, while its account of the relics now in Naples speaks of 1492 and Alfonso II of Aragon. Relics identified as belonging to 240 of the Otranto martyrs are kept today at the church of Santa Caterina a Formiello in Naples, beneath the altar of the fourth chapel on the left (Archdiocese of Otranto, relics in Naples). So, part of the martyrs' remains rest in Otranto and part in Naples, and both churches honor them.

A chapel for the remaining relics was set up in Otranto Cathedral at the beginning of the sixteenth century. Its present appearance dates from 1693, when Archbishop Francesco Maria De Aste had the Chapel of the Martyrs clad in marble and placed the remains in seven large wall cabinets (Archdiocese of Otranto, cathedral history). The chapel stands on the right side of the cathedral, and the cabinets hold skulls and other bones arranged as relics.

This is the sight that brings most visitors to look up the martyrs. The chapel was made as a place of prayer and veneration, and it is still kept as one. The cathedral's visitor regulations describe it as a place of prayer and recollection and ask for silence inside it (Archdiocese visitor regulations). The Archdiocese presents these remains as relics of saints. Relics of this kind have a long place in Catholic devotion, and our stories on skulls in Christianity and the catacomb saints follow that tradition in other churches.

On 12 May 2013, Pope Francis canonized the martyrs in Saint Peter's Square in Rome. The Vatican press bulletin names the ceremony as the canonization of "Antonio Primaldo and Companions, Martyrs of Otranto" (Vatican press bulletin). In his homily, the Pope described them as about 800 people who survived the siege and invasion of Otranto, were beheaded near the city in 1480 and refused to deny their faith.

Antonio Primaldo is the one name that leads the group, and the others are honored together as his companions. The canonization is the Church's formal statement of its belief about them.

The skulls are not the only thing to see in the cathedral, and they are far from the oldest. Otranto Cathedral was consecrated on 1 August 1088. Its floor holds a large mosaic, commissioned by Archbishop Gionata and made by the priest and monk Pantaleone between 1163 and 1165, more than three centuries before the events of 1480 (Archdiocese of Otranto, cathedral history).

The Archdiocese describes the mosaic as representing the "History of Salvation." It runs through the central nave, the transept and the apse, and it is crowded with figures: a great Tree of Life, scenes from the Bible, animals, human figures and medieval imagery (Visit Puglia). Visitors walk over centuries of story on their way to the martyrs' chapel.

Look up and around as well. The cathedral keeps its Romanesque structure, a crypt, a bell tower, a Moorish-style wooden ceiling and a silver antependium, the decorated front panel of the high altar. Restoration of the mosaic between 1986 and 1992 also brought older layers to light beneath the floor: remains of an early Christian church, a late Roman mosaic dated to the fourth or fifth century and two Messapian tombs (Otranto Welcome).

Yes, you can visit the Otranto skulls. The Chapel of the Martyrs is inside the cathedral, and it is open to visitors when the cathedral is open. The Archdiocese's notice dated 4 February 2026 sets out the arrangements from 1 March 2026: visiting the cathedral on your own remains free, while a €2 ticket applies to individuals and groups visiting with a guide, tour leader or teacher for a guided visit or art lesson. Groups of eight or more must book through the cathedral's reservation system, and the ticket office is at the Diocesan Museum in Piazza Basilica (Archdiocese access notice).

The cathedral's official page lists opening hours of 8:30 to 12:00 and 15:30 to 18:30. Hours can shift with the season and with services, so confirm them with the Archdiocese before you travel (Archdiocese cathedral page).

The cathedral is a working church, and its visitor regulations of 27 February 2025 set out how to behave inside: dress decorously, bring no food or drink, bring no animals, use no flash and keep your voice low. Silence is asked for in the Chapel of the Martyrs. Guided visits are not allowed during Mass, the Rosary, Adoration or other communal prayer, and guided tours are limited to thirty minutes (Archdiocese visitor regulations). If you would like to take a photograph of the relics, follow the rules posted in the cathedral and ask the staff first.

If chapels of bones draw you, Otranto belongs to a wider family of places. Our guide to ossuaries around the world includes Portugal's Chapel of Bones in Évora, the Capuchin Crypt in Rome and the Sedlec Ossuary, and closer to Otranto in spirit, Milan's San Bernardino alle Ossa and Spain's osario de Wamba. What sets Otranto apart is that the Church venerates its bones as the relics of saints.

People come to the martyrs with a few questions again and again. Each answer below opens with the short version.

The skulls of Otranto have been in the cathedral for more than five hundred years, moved first from a hillside, then to a nearby church, then into the cathedral and finally into the marble chapel of 1693. Through every move they have been treated as what the people of Otranto believe them to be: the remains of their own townspeople, honored as saints. When you stand in the Chapel of the Martyrs, you stand among them, above a mosaic that was already three centuries old when they died. A quiet visit is the best way to meet them.

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