This two-coin set is one of the "historic" issues by the Royal Mint combining a newly released coin with historic coins taken from circulation.
The mint says about it:
"On D-Day, 6 June 1944, more than 132,000 ground troops and 18,000 paratroopers successfully stormed five assault beaches along the Normandy coastline in France. By gaining a foothold on mainland Europe, the Allies were able to open a second front against Germany that helped turn the tide of the Second World War. This ten-coin set has been curated to mark the 80th anniversary of D-Day and it includes a gold Proof edition of the coin we have struck exclusively to mark the anniversary. The set also comprises the nine UK circulating coins from 1944, which all feature Humphrey Paget’s coinage portrait of King George VI on the obverse."
The 50p coin is in 22-carat gold and in proof grade, while the historic coins are circulated in "fine or better" grade.
he set comes in a luxury timber presentation box, with a numbered Certificate of Authenticity. | 
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