The name of Saint Ambrose has always been linked to Milan, of which it is the patron. The figure of this wise doctor of the Church is not known and understood in all its true and great historical dimension. December 7 is celebrated as the acclaim as a bishop of Milan: why is it called “acclamation” and why was it so important to be celebrated every year since 374? Ambrose, a member of a senatorial family of the Roman aristocracy, Aurelii, was born in 339/340 AD in Trier, in present-day Germany. After the death of his father he moved to Rome. At 31 he was appointed governor of the Emilia and Liguria provinces, with the capital Milan. In the city there were clashes between Christians and Aryans and it was during one of these that he was acclaimed by the voice of a child, followed by all the people, “Ambrose bishop”. Various attempts were made to avoid the appointment, as illustrated by one of the panels of the splendid golden altar, a Carolingian masterpiece, in the Basilica of Saint Ambrose. He was baptized on November 30th 374 and seven days later he became bishop. He then began an important phase of restoration of the Church of the West, building the four early Christian basilicas for the city of Mediolanum and producing a wide range of writings, theological treatises, epistles and exegetical works. He was also the founder of the Ambrosian rite still in use. The painting shown here belongs to the Carratelli collection and is a valuable work by Mattia Preti. This masterpiece restores the saint’s personality as described by his biographer, Paolino da Milano, solitary and meditative, seated at a desk intent on composing his writings. With one hand he squeezes the stirrup, his main attribute, which would allude to the episode of the punishment of the Emperor Theodosius for the events of Thessalonica.