By 274, the Emperor Aurelian was determined to shore up stability, with a reform of the silver coinage high on his manifesto. Sadly, says Dominic Rathbone, professor of ancient history at King's College London, the result was chronic inflation.

"He introduced a new silver coin but retariffed it. They would only accept the new coins back [as taxes]."

In effect, people were receiving their incomes in old debased coins, but were being asked to pay their taxes in the new improved coinage.

Sort of our situation in reverse. We bought our shares with good coin, but now Aurelian wants us to take a debased amount to return them.