From the reign of Queen Elizabeth I (AD 1558-1603) onwards, silver from mines in Cardiganshire were sent to London to be made into coins at the Royal Mint. The coins sometimes bore the distinctive feathers badge of the Prince of Wales.

In 1636 the lease of the Cardiganshire Mines Royal was bought by Thomas Bushell who introduced improved mining techniques. He was empowered to establish a mint in Aberystwyth Castle which produced its first silver ingots in 1638. The dies (the stamps for making the coins) were engraved in London and supplied ready for use.

Bushell produced half crowns, shillings, sixpences, half groats (silver coins worth two old pence) and pennies. Later, halfpennies, groats and threepences were added. Within a few years the mint provided about £10,000 in silver coin. As well as the Prince of Wales feather motif some of the coins also bore the design of an open book, perhaps to demonstrate the honesty of the coin maker.

The last delivery of coined money from Aberystwyth was in September 1642. After this Charles I (reigned 1625-49) ordered the mint to be moved to Shrewsbury in England which was one of his bases during the First Civil War.