I am continuing a reply I made on FAC about when to start the beginning of LRBC's, if for example you wanted to collect one coin from each Emperor of this period. The date of A.D. 294 was given as the best (not by me) and it seemed, only real answer. This is the date Diocletian introduced the follis. It is a fine answer if you want an easy one that does not involve much thought or discussion on the question. To use an analogy, it is the difference between painting with a small brush or a broad brush...I prefer a broad brush, as you can cover more area.
There is certainly no continuity from A.D. 294 onwards with the coins-- look at an early follis of around 295 of say 25mm and 10+ grams and compare to a later follis around A.D. 330 of 15mm and 2 grams- are these the same coin type? Besides both being called a follis, the only thing they have in common is that they are bronze coins. I think that the word "bronze" is the key to the phrase Late Roman Bronze, so we must look at bronze coins in the entire Late Roman period. If you must start with a coin reform, why not Aurelian? This is circa A.D. 275, but I don't think it is early enough. I think you must start by looking at the silver antoninianus, until it becomes debased billon and eventually it is just a bronze coin...a Late Roman Bronze coin. This happened circa A.D. 250 and I would include all bronze ants as LRBC's and that is why I would start the LRBC period with RIC V, which starts with the reign of Valerian in 253, but the shift to bronze is not readily apparent until the reign of Gallienus.
I can't imagine not calling coins of Claudius Gothicus (A.D. 268- 270) LRB's or what about the Gallic Empire coins from Emperors like Postumus, Victorinus and Tetricus. It seems easy enough to call all these bronze coins from this period Late Roman Bronze Coins as they share the necessary attributes- they are bronze and they are from the Late Roman period. Of course, this is my opinion and other opinions may differ, but my point is that there is no hard and fast date to say when Late Roman Bronze coinage began.
