In the first century Pliny bemoaned Rome's trade deficit with the prosperous kingdoms located along the Silk Routes. According to his account, the equivalent of one million aureus coins such as this example were exchanged per year in India, East and Central Asia for silk and other luxury goods. This was much to the benefit of foreign merchants and craftsmen, and much to the detriment of domestic industries and tradesmen. Also, such a large outflow of gold in the form of coins must have been cause for concern among the empire's finance ministers.

This coin is a testament to the worries of Pliny, as it was discovered in southern India in a hoard along with many other gold coins just like it. Scholars have addressed the question of why the coin was defaced, and two possible explanations have been proposed. The first involves a form of Buddhism that prohibits the reproduction of the human image, and suggests that traders ascribing to this school of Buddhism may have damaged the portrait of Gaius for religious reasons. This, however, does not explain why the image of Gaius's empress on the reverse side was not defaced. For this reason, the second explanation seems more plausible - that the coin was struck with a chisel for practical reasons, in order to determine whether the coin was solid gold or merely plated.¹

(1) See the British Museum web page dedicated to this object.