1 Pound - Elizabeth II Royal Arms, Gold Proof

The 2015 gold proof pound holds a particular significance in the series: it was struck in the final year of the four-sided round pound before the Royal Mint retired the design after thirty-three years in circulation. By 2015, an estimated one in thirty round pounds in circulation was a counterfeit — the highest forgery rate the Mint had publicly acknowledged for any modern British coin — and that figure was the direct administrative trigger for the transition to the twelve-sided bimetallic successor introduced in 2017.