Detail of Decemviri Altarpiece (1495-6) by Perugino

Pinacoteca Vaticana

An entry in the Roman Martyrology under 29th January records: “At Perugia, in the time of [the Emperor] Marcus Aurelius, St Constantius, bishop and martyr, who together with his companions received the crown of martyrdom for the defence of the faith”.

St Constantius is listed under the same date in the Hieronymian Martyrology and Perugia is given as his place of execution. 

The four known versions of the legend of St Constantius are designated BHL 1937-40.  (A copy of BHL 1937 is preserved under 29th January in the Leggendari del Duomo).  These record the martyrdom under the Emperor Antoninus.  He suffered torture under officials named Lucius and Carsilius, and then took refuge in the house of a certain Anastasius “ad locum qui dicitur Monticellus” (at the place called Monticellus), but both were subsequently arrested, together with their colleague Carpophorus.  They managed to convert their oppressors, and were released.  However, other officials questioned St Constantius as he travelled along the Via Salaria, and he was arrested when he admitted that he was trying to visit the Spoletan SS Concordius and Pontian.  He was imprisoned in Assisi and then executed “in trivio Fulgineato, non longe a civitate ipsa” (at the crossroads, not far from Foligno).  An angel appeared to a perugian noble called Levianus, instructing him to find the body and to bury it with honour.  He duly found it and took it for burial at a place “Areola”, which presumably refers to the location of the present church of San Costanzo, Perugia.

St Constantius, who is said to have been the first bishop of Perugia, was adopted as a patron saint of the city in 1310 (probably after lobbying by the friars of San Domenico).

His relics were apparently re-discovered in the church of San Costanzo in 1781 and translated to a new altar there in 1825.

Cult of St Constantius outside Perugia

A church (12th century) outside Porta del Cieco, Trevi (see the Walk around Trevi), which stood on the presumed site of the martyrdom, was demolished in 1890.  Virginia Ryan, the author of "Where the Cypress Rises", writes about her discovery of what seem to be the remains of this church in her garden there.

The canons of the Duomo of Orvieto also had their own church of San Costanzo (dedicated to St Constantius), the foundations of which were discovered under the nave of the present Duomo in 1955-6.