The follis was first issued in 294 AD by Diocletian and began as a very large bronze coin with a silver wash about the size of a US half dollar. Over the next few decades the coin shrunk to the size of a denarii (about 15mm) and smaller then a dime by the mid 4th century. On a follis the emperor is always shown wearing a laurel wreath, with a low relief stylized. bust. They look similar to the Antoniniani but were issued after the Antoniniani were discontinued.