Also, what might be an equally challenging question is how many coins can you think of that do not have the name of the issuing nation on them? Or lacking a denomination?
The vast majority of coins have neither the name of the issuing nation, nor the denomination on them. Roman coins are a good example. The name of the nation became a fixture only after the French revolution. Before, all we have is titles of nobility and arms, on small coins often not even that, especially before the high middle ages. The same for denominations: they were the exception, rather than the rule until the French revolution. Britain often didn't put them on until decimalization and the US still doesn't use numeric denominations on its coins and tends to use nicknames instead.
The reason is simple. Most people couldn't read. They judged a coin on pictures and patterns, not on text. That is why you find that on older coins, each denomination in a series is different in dsign from the others (it is still that way in the US). That is also the reason for the exception: Spanish coins very often have a denomination. That is because Spanish coins of all denominations used the same design. Of course, illiterate Spaniards became very good at judging a coin's weight and size.
Peter