St. Maurus, son of the Roman patrician Eutychius and first disciple of St. Benedict, according to the Dialogues of St. Gregory the Great, hastening in obedience to help St. Placid who was drowning, walked dry footed on Nero’s lake at Subiaco.  Died in 584, in France.
(Source: Fr. Lasance, The New Roman Missal)