The martyrs Cantius, Cantianus and Cantianilla and their tutor Ptotus were killed the day before the calends of June, twelve miles from Aquileia, across the River Isonzo in a place called ‘Ad Aquas Gradàtas’.
This information comes from a passage in Acta Martyrum, ancient documents written in Latin perhaps as early as the fifth or sixth century AD recording the martyrdom of the early Christians.
The three siblings and Protus were put to death on 31 May AD 301 in a small town in northern Italy, now called San Canzian d’Isonzo, not far from Aquileia, one of the largest and most prosperous cities in the whole Roman Empire, for refusing to renounce their Christian faith.
The martyrdom actually took place at in Aquas Gradàtas, perhaps today’s Grodate area. And it is precisely here that since time immemorial a procession in memory of Cantius, Cantianus and Cantianilla winds its way along the streets every 31 May.
The three were buried in a single tomb to the north of the present parish church, on the site of a luxurious Roman villa that perhaps belonged to their family. News of the martyrdom spread and the growing flow of pilgrims led to the first building being erected in their memory around the mid fourth century. Two centuries later, this was replaced by a second, larger basilica. This was decorated with a beautiful mosaic that still bears the signs of the huge fire that destroyed it completely in the tenth century. The present parish church was built about five hundred years later, being completed in 1593.
Protus was buried not far from the three martyrs’ tomb. Here too a memorial hall was built over the tomb in the fourth century. This building went through three distinct phases, ending with the present small church of San Proto, which dates from the fifteen or sixteenth century.
San Canzian d’Isonzo records the story of the three siblings and their tutor, a story that begins with their martyrdom and continued over the centuries as the area became a place of pilgrimage. Monuments were erected in their memory and basilicas were built so the visiting Christians could worship appropriately. The small town was also a lively and prosperous Roman town in its own right before these events took place. Many artefacts and material remains from this period are preserved in the Antiquarium’s exhibition, where visitors can let the ancient San Canzian cast its spell and imagine how life was lived here long ago.