Saint Placidus, disciple of Saint Benedict, the son of the patrician Tertullus, was brought as a child to Saint Benedict at Sublaqueum (Subiaco) and dedicated to God as provided for in chapter 69 of Saint Benedict’s Rule. Here too occurred the incident related by Saint Gregory of his rescue from drowning when his fellow monk, Maurus, at Saint Benedict’s order ran across the surface of the lake below the monastery and drew Placidus safely to shore. It appears certain that he accompanied Saint Benedict when, about 529, he removed to Monte Cassino, which was said to have been made over to him by the father of Placidus. Of his later life nothing is known, but in an ancient psalterium at Vallombrosa his name is found in the Litany of the Saints placed among the confessors immediately after those of Saint Benedict and Saint Maurus; the same occurs in Codex CLV at Subiaco, attributed to the ninth century.
There seems now to be no doubt that the “Passio S. Placidi”, purporting to be written by one Gordianus, a servant of the saint, on the strength of which he is usually described as abbot and martyr, is really the work of Peter the Deacon, a monk of Monte Cassino in the twelfth century. The writer seems to have begun by confusing Saint Placidus with the earlier Placitus, who, with Euticius and thirty companions, was martyred in Sicily under Diocletian, their feast occurring in the earlier martyrologies on 5 October. Having thus made Saint Placidus a martyr, he proceeds to account for this by attributing his martyrdom to Saracen invaders from Spain — an utter anachronism in the sixth century but quite a possible blunder if the “Acta” were composed after the Moslem invasions of Sicily. The whole question is discussed by the Bollandists.
- Gilbert Huddleston. “Saint Placidus”. . Saints.SQPN.com. 20 August 2013. Web. 27 February 2015. <>