I never grow weary of the coinage of the Constantinian dynasty but I'll post the two that made it possible: Constantius I "Chlorus" and Helena. Their one offspring was Constantine the Great, after which Constantius divorced Helena and married Theodora - for the sake of political advantage. One of my favorite coins of Constantine I is this follis from the Langtoft hoard.
Constantine the Great's first son was Crispus, by a certain Minervina. Nothing is known of her, but she was likely a concubine, as contemporary sources make no mention of a divorce when Constantine marries Fausta. Crispus met his death at his own father's hand, after Fausta accused him of rape. Fausta was later found out to be lying, and she gets suffocated in a steam bath - basically boiled alive. Just another day in the Roman empire. Coins of father and son. This follis of Constantine is an unlisted variety. The combination of mint and field marks with the portrayal of Sol facing/turned left is rare. Crispus marks a very short dead-end in the Constantine family tree. If he had any progeny, they are lost to history.
On the great majority of coins of Constantine he is Augustus (AD 307-337). Less common, and more desirable, are the early issues (306-307) when he was Caesar (NOB CAES). Still less common and even more desirable, in my opinion, are coins when he was "FILL AVGG" ("son of the Augusti," from some eastern mints, 308-310). For the story of this title, see coins 18-25 on my page: http://esty.ancients.info/FILAVGG/
Here are coins of Constantine I and the ill-fated Fausta. The follis of Constantine is the scarce, unusual, and extremely busy DAFNE reverse type. If you collect this coin, it behooves you to spend the money for a well-struck, well-preserved example. The reverse detail can be quite stunning...
This is one of the main branches of the Constantine family tree, within which lies an enormous amount of interest to collectors. Coins of Constantine II, brothers of the same mint (Lugdunum) with marks PLG and SLG in exergue. Phoenix and Falling Horseman types of Constantius II... And a favorite Emperor Leading Captive type of Constans...