Recently I announced a new educational web site on the coins of the First Tetrarchy (Diocletian, Maximian, etc,):http://augustuscoins.com/ed/tetrarchy/
br / Now I am announcing a new educational web site on coins of the Second Tetrarchy:http://augustuscoins.com/ed/tetrarchy/Second.html
For numerous related pages, see the site of links here:http://augustuscoins.com/ed/tetrarchy/extra.html
The page of links has links to these pages:
"Introduction to the Roman coins of the First Tetrarchy: Diocletian, Maximian, Constantius, and Galerius" [The first link above]
"Coins of the First Tetrarchy: Pre-Reform Coins of Diocletian, Maximian, Constantius I, and Galerius"
"Follis types of the First Tetrarchy, 293-305 CE"
"GENIO POPVLI ROMANI: a common late Roman coin type"
"SACRA MONETA: a common late Roman coin type"
Abdication types of Diocletian and Maximian
How to distinguish coins of Maximian from coins of Galerius
"Roman coins of the Second Tetrarchy" [The new, second, link above]
How coins are dated to the Second Tetrarchy
The "radiate fraction" a.k.a. "post-reform radiate" denomination.
The silver argenteus denomination.
I've been busy trying to make the coins of 284-306 understandable, especially to those who already collect ancient coins but don't know much about coins of that period. It is pretty complicated because there were four rulers at a time, not just one followed by another as in the early centuries. The history is fascinating and the coinage complicated, but not too complicated, and not too expensive. Take a look around and bookmark the links page because it would take days to read it all.
Constantius was western Caesar in the First Tetrarchy and became western Augustus in the second. Here is a new type issued under the Second Tetrarchy:
Constantius as Augustus
28 mm. 8.84 grams.
IMP CONSTANTIVS PF AVG
FIDES MILITVM AVGG ET CAESS NN
Fides standing left holding standard in each hand
RIC Aquileia 60a