Coins played different roles in the ancient and medieval worlds from those that they play in the economy today. In the late antique and early Byzantine world -that is, roughly between 300 and 800 -there were in a sense two currencies: gold coins and base metal (copper) coins. Both were minted and distributed by the state, but the gold solidi (in Latin) or nomismata (in Greek), introduced in 309, were by the end of the fifth century in practice used above all for the payment of tax and for major transactions such as land sales, while the copper coins (nummi, replaced in 498 by folles) were broadly the currency of market transactions. 1 Another striking difference is that late antique and Byzantine coin types changed with great frequency: as an extreme example, Maria Alföldi catalogued over seven hundred different types for a single emperor, Constantine I the Great (306-37, sole ruler from 324). 2 There are many reasons for this, but one of the most important has to do with communication: centuries before the advent of the press, images on coins were a means to circulate information about the state. This is particularly true of the first three and a half centuries covered by this article. While the extent to which coins were used in daily exchange transactions is still uncertain, and was very variable, the frequency with which they appear in archaeological excavations of urban sites throughout the former eastern Roman empire until 658 indicates their wide diffusion. After this, gold coinage continues in Gender & History