Hildegarius was a Benedictine monk of Saint-Denis who became bishop of Meaux around 856 and died in 873 or 876. After the Viking sack of his city in 862 he composed the Life and Miracles of Saint Faro, his seventh-century predecessor, crediting the saint with the preservation of the church of Meaux — one of the fullest episcopal biographies of the Merovingian age.