Benedictine monk. As a young boy he was entrusted to Benedict at Subiaco to be educated and to become a monk. He once fell into the lake there and was rescued by Maurus, according to Gregory's Dialogues. A forgery of Peter the Deacon of Monte Cassino made him a martyr in Sicily with thirty companions, who in fact suffered before he was born—they were alleged to have been killed at Messina by Saracen pirates from Spain at a time long before the Moors had even reached Spain. However, this fantasy was ‘confirmed’ by the discovery of a deed of gift, purporting to be from Tertullus (Placid's father) to St Benedict, giving him lands in Sicily; in 1588 relics were found at Messina which were believed to be those of the martyred Placid and companions. This led to the feast of Placid on 5 October being celebrated very widely and in particular by Benedictine monasteries, who regarded him as the patron of novices and customarily assigned this day to them as that on which they performed the liturgical functions usually reserved to the professed. In 1915, however, the Benedictine liturgical commission proposed to suppress this feast and to celebrate the boy Placid with Maurus. This, however, was refused until the next revision which took place about forty years later when the combined feast of Maurus and Placid was authorized for 5 October. Among the medieval calendars that of Abingdon kept Placid as ‘abbot and martyr’.
E. Caspar, Petrus Diaconus und die Monte Cassineser Falschungen (1909); J. McCann, St Benedict (1938), pp. 282–91; B.L.S., vii. 81–2.