2 Pounds - Elizabeth II Hercules and the Mares of Diomedes, Silver Proof

The fourth labour of Hercules — capturing the man-eating mares of the Thracian king Diomedes — was one of several subjects Gibraltar selected for a 1999 series commemorating the twelve labours. Gibraltar had been issuing ambitious collector silver throughout the 1990s, leveraging its Crown dependency status to produce issues with no obligation to circulate, effectively functioning as a bullion-adjacent commemorative program aimed squarely at the thematic collector market.

The .9999 fineness is notably purer than the .925 sterling used on most British Commonwealth proofs of the period.