In 2005 to commemorate the 200th Anniversary of Horatio Nelson's Death, the Royal Mint released a very Limited Issue Horatio Nelson Piedfort £5 Five Pound Platinum Proof Coin struck in solid fine 999.5 Platinum weighing three ounces of pure Platinum Certified Slabbed and Graded by PCGS as PR69 DCAM.
The reverse is a portrait of Horatio Nelson in the uniform of Vice Admiral by James Butler and the obverse is a portrait of Queen Elizabeth II by Ian Rank Broadley. Piedforts are coins which have been specially struck on thicker than normal blanks.
As their name suggests they are closely associated with France, where from the twelfth century they were apparently issued by the Kings as presentation pieces.
In Britain the practise of striking piedforts is later and less frequent, but medieval and Tudor examples are known.