WHY??? - Why did the Byzantines make cup-shaped "coins"? I just purchased Mr. Sayles' Byzantine Coin book & even HE doesn't know why they did it!! Any quasi-reasonable wild guesses?? Thanks, Bill.
I dont know but on wikipedia it says "The exact reason for such coins is not known, although it is usually theorized that they were shaped for easier stacking" http://en.wikipedia.org/wiki/Byzantine_coinage
I don't know why either but I do know the cup shape makes it difficult to photograph and get everything in focus.
I'm a bit shaky on the chronology, but I believe what happened was that they issued a flat coin of a particular shape and fineness (solidus) and they wanted to issue new coins of a lower standard. But the solidus was a popular trade coin and was used internationally. So, they struck scyphate gold coins for their own territory. The real question is, why did this practice persist and spread to the other metals? Probably, as randygeki said, so as to make them stackable.
I think it has to do with the minting technology at that time. I am not clear on how ancient coins were struck so I might not be the best person to comment about it.
I don't know much on ancients, but if I had to guess I'd say because of the thinness of the coin a cupped shape adds to it's surface area preventing splitting and bending over time. Or, they were used as really small beer mugs in pubs. I don't know. Guy~
I dont think its the technology, the byzantines could strike and did strike coins the same as they had always been struck. That would be, in short, two etched dies, a planchet and a hammer. I would think cup coins were oversized planchets struck with a cup shaped die on one side. So the only difference is the shape of the die and size of image to planchet. My vote has always been the stackable explination, or some reasoning similar as the one expressed by Ardatirion.
Except in the case of the Byzantine AE's and AV's, I don't see other scyphate coins being particularily conducive to stacking. This is what George Hill has to say in Ancient Methods of Coining: "A curious development, found especially in decadent or barbarous coinages, is what is called the scyphate or cup-shaped fabric. The obverse, although its relief is not high, is strongly convex, the reverse strongly concave, so that the coin takes the shape of a small saucer. The object of this fabric may possibly have been to fix the blank firmly between the dies in striking. It is characteristic of certain barbarous Celtic coinages, of one group of coins of the Himyarite rulers of Soutehrn Arabia in the first centruy after Christ, and of the later Byzantine coinages, as well as of the some Balkan coinages under Byzantine influence." This is my only example of what he refers to directly - Himyarties (Arabia Felix) 1/2 denarius AR 50-150 AD Amdan Bayyin Yanaf Raidan mint
