[dghughes]

> how did all these countries manage to find enough gold

They may not have. Some gold mixed with silver or other metals may have been common. In other words counterfeiting whether officially sanctioned or by thieves was probably not uncommon.

[lostlogin]

I have a ‘silver’ Roman coin, but it’s a thin layer and it’s bronze underneath.

[tnecniv]

Rome certainly did that at different points when funding was needed