The radiatus was a Roman coin denomination introduced during the reign of the Roman Emperor Aurelian (270–275 CE) as part of a broader series of reforms aimed at stabilizing the Roman economy, which was facing significant inflation and devaluation of its currency. Aurelian sought to create a more reliable monetary system, and the radiatus was one of the key innovations in this process.

The radiatus was a silver coin that typically featured a portrait of the emperor on the obverse, often with a radiate crown symbolizing the emperor’s divine power and association with the sun god, Sol. This imagery was a direct reference to the emperor’s role as the protector of the empire, and the radiate crown became a recurring symbol in Roman imperial coinage. The reverse of the coin often depicted a variety of motifs, including military and religious symbols, which reinforced the authority and divine favor of the emperor.

The radiatus was initially introduced as part of a new silver-based currency system, replacing the previous antoninianus, which had been debased and had lost much of its silver content. The radiatus, with its higher silver purity, was an attempt to restore trust in the Roman currency. However, despite these reforms, the coinage system continued to face challenges due to inflation and the declining value of silver. Over time, the radiatus was replaced by other coin denominations as the Roman Empire experienced further economic difficulties, especially during the later stages of the 3rd century CE.