Byzantine Trachy, Christ & Mary

 Sporting a curious cup shape, nobody knows for sure why the Byzantine Empire struck these coins curved instead of flat. It was no easy task either—in an era before precision tools, painstaking care was required. Theories have included making them easier to stack or harder to counterfeit, but the leading answer is that it made the thin coins harder to bend.

The Byzantine Empire (also known as the Eastern Roman Empire) was a continuation of the ancient Roman Empire. It technically formed in 395 AD when the empire split into East and West, though Romans at the time hardly made that distinction. While the Western Empire would fall in the late 400's AD, Byzantine rule lasted well into the Middle Ages until 1453.

These coins are a product of a deeply religious society—each features imagery of Jesus Christ and/or the Virgin Mary on the obverse, and one of about a dozen 13th century emperors is shown on the reverse. Each coin measures around 0.6 to 0.7 inches (15 to 18 mm) in diameter, and is made of a copper-silver alloy known as billon. They have been inspected by an ANA Certified numismatist and are guaranteed authentic.

A mosaic of Justinian I, one of the early Byzantine emperors (via Wikimedia)