Aureus (Coin) Portraying Emperor Diocletian

Portraits of important people appear on local currency all around the world. The same was true in ancient Rome, which began producing its first coinage in the late 4th century BC. Early coins depicted the heads of gods and goddesses on the front side, often in profile, while the back depicted animals, natural resources, symbols, and references to historical events. It was not until 44 BC that the portrait of a living person—Julius Caesar—appeared on coins. Thereafter, profile portraits of rulers or other members of the imperial family became the standard subject on coins throughout the Roman Empire.

Inscriptions on coins help identify the ruler. While the front side depicted the sovereign’s portrait, the back was often used to communicate the ruler’s accomplishments or aspirations. Until Late Antiquity, portraits usually appeared in profile. The tiny images were carved by engravers into bronze dies, with one for the front and another for the back. The coins were then struck, one by one, in a process similar to how coins are created today.

The fourth century was a time of tremendous political, social, and religious strife within the Roman Empire, but the imagery on these coins tells a story of an unbroken chain of powerful rulers. Diocletian (reigned 284–305) enacted a series of administrative, military, and monetary reforms that brought an end to the chaos of the third century. He divided the vast empire into western and eastern halves and assigned their administration to four men, the Tetrarchy. Each half was governed by two tetrarchs, one senior and one junior in status. Portraits of these rulers are generic-looking, without individualized features, to reinforce the unity of their joint rule.