Early Christian churches in Milan
Early Christian churches in Milan are the first churches built immediately after the Edict of Milan (Edictum Mediolanense) in February 313, issued by Constantine the Great and Licinius, which granted tolerance and religious liberty to Christianity within the Roman Empire. "Mediolanum" was the name of the Roman city that became present-day Milan.
Source: Wikipedia — Early Christian churches in Milan (CC BY-SA 4.0)