The pound coin was first produced in 1983 and replaced the Bank of England £1 note. The original pound was a round coin and was produced in the same shape until the last round coin known as 'The Heraldry' in 2016.
The round pound coin of which roughly one in 30 is a counterfeit, the equivalent of around £50m, was withdrawn from circulation on the 15th October 2017 and was replaced by the new 12 sided coin. The new coin has been designed to prevent forgeries being made as it contains several security features: 
12-sided – its distinctive shape makes it instantly recognisable, even by touch.
Bimetallic – it is made of two metals. The outer ring is gold coloured (nickel-brass) and the inner ring is silver coloured (nickel-plated alloy).
Latent image – it has an image like a hologram that changes from a ‘£’ symbol to the number '1' when the coin is seen from different angles.
Micro-lettering – it has very small lettering on the lower inside rim on both sides of the coin. One pound on the obverse “heads” side and the year of production on the reverse “tails” side.
Milled edges – it has grooves on alternate sides.
Hidden high security feature – a high security feature is built into the coin to protect it from counterfeiting in the future.
This coin was first circulated on the 28th March 2017. Firstly the 2016 12 sided coin was released and was followed at the end of May by the 2017 coin.
The obverse showing the queens head was designed by Mr Jody Clark and the reverse was designed by David Pearce