The Florin or Double Leopard was an attempt in 1344 by English king Edward III to produce a gold coinage suitable for use in Europe as well as in England (see also Half Florin or Leopard and Quarter Florin or Helm). It was 108 grains (6.99829 grams) of nominal pure ('fine') gold and had a value of six shillings (i.e. 72d).
The florin, based on a French coin and ultimately on coins issued in Florence, Italy, in 1252, was a standard coin (3.5g fine gold) widely used internationally.
Unfortunately the coins were underweight for their value, resulting in them being unacceptable to merchants, and the coins were withdrawn after only a few months in circulation, in August 1344, to be melted down to produce the more popular gold Noble (9g gold valued at 6/8 (i.e. 80d)).
The obverse of the coin shows the King enthroned beneath a canopy, with two leopards' heads at the sides (the leopard being the heraldic "lion" on the English coat of arms); the legend is (Edward by the Grace of God King of England and France Lord of Ireland). The reverse of the coin shows the Royal cross within a quatrefoil, a leopard in each spandrel; the legend is (But Jesus passing through their midst went his way).
Only three examples of this coin are known to exist: two discovered on the River Tyne in 1857, and one discovered in January 2006. The latter coin was sold at auction in July 2006 for a record price for a British coin, of £460,000. The first two discovered are displayed in the British Museum.