No likeness on file
Calocerus of Rome
martyr at Rome
SaintResearchedDate unknown
Feast: 19 May (not on the universal Roman calendar; kept in the Roman Martyrology or local calendars)
Born
—
unknown
Died
—
unknown
Beatified
—
not on record
Canonised
—
not on record
Who they were
Again at Rome, Saints Parthenius and Calocerus, martyrs, who under the emperor Diocletian bore outstanding witness to Christ.
The miracles
There was never a formal cause: he has been honoured as a saint since before the Church's formal processes began.
Why that counted as sanctity
The Roman Martyrology remembers him on 19 May as a martyr who bore outstanding witness to Christ at Rome under the emperor Diocletian.
Sources
- Roman Martyrology, 19 May (Italian Bishops' Conference, Santo del giorno)
- Wikidata Re35457a9 — dates, feast day and identifiers (CC0)
Checked against the sources listed on 22 September 2026. Corrections welcome.