The Rediscovery of the "Adventus Augustorum" Aureus of Diocletian

This Note deals with an apparently unique Diocletian aureus from the Medici and Grand-ducal collections originally in the Uffizi Gallery and now in the coin cabinet of the National Archaeological Museum of Florence. It is argued that the issue celebrates a meeting between Diocletian and Maximianus Herculius in Milan in Dec. 290- or Jan. 291.