I am puzzled by the fabled existance of the Diocletian Denarius. Apparently, this was the last denarius ever minted (although some say the Aurelian 'Victory' denarius was the last one). I have never even seen a picture of a coin of Diocletian described as a 'denarius', but, as the term survived down to the present day, and we do not really know what the Romans called the lower denominations of Diocletian's reformed coinage, is it possible that some of the smaller bronze coins often called 'AE3' are in fact, denarii?
I thought the smaller coins were either follis, half follis, quarter follis, etc. AE3 is just the size, but like all coins the follis got smaller as time went on.
I don't really know anything about any denarii minted under Diocletian before his coinage reform (they would have been rather ceremonial pieces that would be mostly bronze by that point and not really made for widespread use), but the smallest coin following his coinage reform was worth one denarius, and there is the possibility that it was called a denarius (we really have no idea what it was called). However, these weren't made for that long, and we know that the other coins were worth more than one denarius, and inflation shrank them to what we call AE3s and AE4s, so those later coins are not denarii.
Would the smallest coin the same as what we call a quarter follis? I know half and quarter follis, (what we call them), were made after the reform and then went away as the follis shrank.
From what I understand, no one really knows what they were called and the term 'follis' (as with the antoninianus) is a name made up by later numismatists and historians to refer to these coins...
Agree. To go further, even the terms like quarter and half are open to discussion. I side with the camp that ranks them as 1/5 and 2/5 of the large follis making the term denarius not all that unreasonable for the smaller, laureate one. I don't have a Diocletian but do have a Constantius I. With no silver, I'd not apply the term denarius. Perhaps the better candidate for the term and last position would be the Carausius which was good silver and possibly a special issue presentation item rather than a circulating coin. They made the news recently when some were found in the Frome hoard: http://www.flickr.com/photos/finds/sets/72157624319051565/?page=2
