In 2017, the Nickel Brass, round type of one pound coins were discontinued in the United Kingdom and the denomination was changed to a 12-sided bimetallic coin known as the "Nations of the Crown £1" due to its reverse designs which represents the floral emblems of the four constituent nations - England, Scotland, Wales and Northern Ireland.
The new coins entered circulation in 2017, with the bimetallic coins being prepared earlier and dated 2016.
In March 2017, the Royal Mint released this special limited issue set with two coins (both dated 2016): a specially struck "Last Round Pound" (not issued for circulation), and a version of the new 12-sided coin with a special "crosslet" privy mark on the obverse. | 
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