The world has used gold as money for thousands of years because its purchasing power cannot be inflated away by governments and banks. Gold is mined at roughly the same pace as the increase in world population.
Well, you are forgetting 17th century southern Europe when Spain imported so much plundered gold from the New World that it caused widespread inflation.
And the gold rush of 1849, which caused an inflationary blip, too. But these things tend to settle out a hell of a lot faster when there's no printing press going full-speed.
It's also self-correcting somewhat. Once the price of gold falls in such a scenario, the incentive to mine/conquer more drops greatly