Roman Gold Revealed at the RISD Museum

From its inception in the 4th century A.D., Roman coinage served a simple purpose beyond monetary transactions—propaganda. Across the roughly 2,000 years of Roman, and later Byzantine, history, imperial coinage did just that: operated as a tool to spread messages of power, religion, and dynastic plans across the empire. 

Among all the denominations that came and went during those centuries, the gold solidus—introduced by Emperor Constantine I, also known as Constantine the Great—stands alone as the longest lasting and offers powerful insight into the immense change that it witnessed. Today, this history isn’t just recounted in books—it is preserved in gold, including the numismatic collection at the Rhode Island School of Design (RISD) Museum in Providence, Rhode Island.

RISD’s Hidden Gold

Acquired quietly in the early 1960s, the RISD Museum’s collection of 25 Roman and Byzantine solidi stretches across the coin’s entire lifespan from the 4th to 11th centuries. These coins have largely been stored in the museum’s archives, with their images available online without complete digitized descriptions and records.

As RISD began to digitize the records of these coins in early 2025, I was able to assist by weighing them with the museum staff and using existing note cards associated with the solidi from their acquisition in the ’60s. I then translated and updated these records using modern resources in preparation for the staff to upload them to the RISD public database. Digitizing these coins entailed researching each specimen one by one, and in doing so, the empire’s history unfolded. These particular coins aren’t significant for their volume, but rather for the timeline and insight into Roman and Byzantine history they offer.

The Solidi

During the crisis of the 3rd century (A.D. 235-284), Rome faced the ultimate test, militarily and monetarily speaking. Roman silver coinage (denarii) went from upwards of 75-percent purity before the crisis, to less than 5 percent under Emperor Gallienus’s reign. The gold aureus also succumbed to these pressures as the coin’s weight and purity began to fluctuate. These inconsistencies led to mistrust in the government, especially among the elites who predominantly used the coin. 

In the aftermath of the crisis, Emperor Diocletian, and later Constantine the Great, aimed to restore monetary stability by replacing the aureus, denarii, and other denominations that rampant inflation and debasement had devalued during the 3rd century. To this end, Emperor Constantine abolished the aureus and created the gold solidus. This new coin, weighing roughly 4.5 grams of pure gold, was significantly lighter and thus more suitable for the new reality of the empire post-crisis. From its inception, the soldius would remain largely stable in its composition of 4.5g of over 95-percent pure gold during its lifespan. Here is an exceptional example of a double solidus (roughly 9g) struck under Constantine the Great at the mint of Trier.

This solidus lasted roughly 700 years until Byzantine Emperor Alexios I Komnenos abolished it in the aftermath of the disastrous battle of Manzikert (A.D. 1071), when debasement would lead to its replacement by the hyperpyron. 

The solidus drastically changed over those 700 years, reflecting shifts in religion, culture, rulers, and imperial messaging. A solidi from the 4th century would most likely display a side-facing diademed bust of the emperor on the obverse and hybrid Christian-pagan imagery on the reverse. This is an example of Emperor Valentinian I, also from the mint of Trier.

Solidi (or nomisma as it would later be called) from the 11th century predominantly featured Christ Pantocrator on the obverse. The emperor appeared on the reverse wearing some form of statesman apparel and holding either a patriarchal cross or imperial military standard. Shown is an example from Emperor Basil II “Bulgaroktonos” (who ruled jointly with his brother Constantine) from the mint of Constantinople.

By the 11th century, toward the end of its life, the solidus took on a scyphate form—gently concave with the center slightly sunken. Across the centuries, the solidus evolved both in form and in meaning, yet its weight and purity remained largely stable and formed the backbone of imperial finances. This longevity immortalizes the coin as a timeline of the Roman and Byzantine worlds, one that institutions, like the RISD Museum, play a crucial role in bringing to light. 

Conclusion

Today, the solidus serves as a reminder of the endurance of an empire and the inevitability of change. The coin reflects transformation across centuries in the Roman and Byzantine worlds. 

My next goals include researching the more specialized and lesser-studied issues of late Roman solidi (such as those minted under Constantius III and the last of the Western emperors). Additionally, I aim to develop a digital exhibit centered around sharing the numismatic reality of this era with a larger audience. Projects like this hold their value in their ability to connect collectors, enthusiasts, and researchers alike with the enduring lessons of the past that remain relevant to us today.