MATERNUS, Saint. — He was already Bishop of Cologne in 313, when Constantine invited him to take part in the Roman Synod to settle the Donatist controversy; in 314 he was again at the Council of Arles for the same reason. He was already dead by 344, for in that year the see of Cologne was governed by his successor Eufratius. Towards the 9th century a very legendary biography of Maternus was written, which made him a disciple of St Peter who had sent him directly to Cologne. He is commemorated on 14 September.
Agostino Amore

Spiritual Maternity of the Blessed Virgin Mary – Madonna of Mercy. Panel painted for the Trinity altar of Pistoia cathedral. Workshop of Filippo Lippi (1466-67) – Berlin, State Museum.