Coin Hoards from the Roman Empire

Ancient Rome had significant trade links with India, particularly during the Roman Empire under the rule of Augustus and onwards. The Silk Road and Indian Ocean trade routes facilitated the exchange of goods to Rome from India, including textiles, spices, gems, and other luxury items.

You can find evidence of this trade between the Roman Empire and India on this interactive map of archaeological finds of Roman coins. Oxford University's Coin Hoards of the Roman Empire collects and maps information about found hoards of Roman coinage in use in the Roman Empire between approximately 30 BC and AD 400.

Map of the Roman Empire

The distribution of found Roman coin hoards closely matches the extent of the Roman Empire (shown here using Hans Hack's Point in History map). Outside of the Roman Empire a few coin hoards have been discovered in Eastern and Northern Europe, fairly close to the borders with the Roman Empire. However what stands out on the Coin Hoards of the Roman Empire map are the clusters of coins discovered in India (and to a lesser extent China). 

The large number of coin hoards found in southern India and in particular in modern day Sri Lanka are evidence of the active sea-route trade between India and the Roman Empire (via Egyptian ports and the Red Sea). According to Wikipedia "the southern (sea) route grew to eclipse and then totally supplant the overland trade route", which is probably why such a relatively large number of Roman coin hoards have been discovered in southern India.

Spices traveling from India would take at least three months to travel to Rome. Stanford University's Orbis (Geospatial Network Model of the Ancient World) doesn't allow us to explore routes from southern India to Rome. However we can explore possible routes from Berenice (a port in Egypt on the Red Sea) to Rome. According to Orbis the "Fastest journey from Berenice to Roma in July takes 42.9 days, covering 3846 kilometers". 

To get to Berenice from southern India would take an additional 30-60 days. According to ChatGPT "it is estimated a journey could take roughly one to two months to go from the southern coast of India to the mouth of the Red Sea. From there, goods might be transported overland to the Nile and then carried to Alexandria or other destinations in Egypt".