The twelve sided threepence coin was in circulation between 1937 and 1971 and was only abandoned when decimal coins were introduced. As children, we grew up with that coin and loved it. Its distinctive shape made it easy to identify even in your pocket.
The existing circular one pound coin has been around now for 30 years and is increasingly subject to counterfeit. There are an estimated 45 million forgeries in circulation. I recall having one once, it was made of soft metal and was rejected by the toll booth at the Mersey Tunnel *.
In a bid to beat the forgers, the Royal Mint have decided to revive the 12 sided design in 2017 with a new one pound coin. They say that it will be the most secure coin in the world and will employ state of the art technologies.
* For my shame, I admit that I did manage to pass it off in a shop.