When Diocletian first instituted a new type of imperial organization based on shared rule and merit (rather than family dynasty), he appointed one co-Augustus, Maximian. They divided the empire between them, Diocletian in the east and Maximian in the west, each attending to the various threats pushing in across the empire’s borders. In 293 CE, each man then adopted and appointed his own junior Caesar, beginning the Tetrarchy – the “rule of four.” All of the men were of Illyrian background, and as such, capable military leaders and strategists. They were also loyal to Diocletian, and the Caesars were even forced to divorce their wives and marry the daughters of the Augusti. The connection between the four men was emphasized in various media, with their iconography often represented with similar features to convey their unity. This aureus features a portrait of Galerius, junior emperor of Maximian; the legend, “Maximian, most noble Caesar” refers to Galerius, but using the adoptive name Maximian (his full name was Galerius Valerius Maximianus) to tie his identity to that of his Augusti. Note his close-cropped beard, which underscored his role as a soldier. The reverse image is a powerful Jupiter clasping a handful of thunderbolts, with the victorious symbol of Rome, an eagle, below. This aureus communicates clearly Roman power and tetrarchic harmony. KHK.