At the time of decimalisation in 1971, the United Kingdom Crown coin (equal to 5 shillings) was redenominated as a 25p coin and pieces struck prior to 1990 - all the way back to 1818 - continue to be legal tender for that amount. The old denomination had been a regular circulating coin in the 19th century, but in the 20th century it became more of a commemorative denomination.
The Royal Mint continued issuing commemorative coins in the same format - using the traditional coin dimensions, but in copper-nickel. These were initially also denominated as 25 pence but the "Crown" was changed in 1990 to a commemorative £5 (five pound) coin, having the same dimensions and weight but with a face value twenty times as great.
The denomination is used to mark special occasions, usually royal in theme, rather than for use in general circulation. Although not circulating, these coins are legal tender.
This commemorative £5 Crown-sized coin was issued as a Christmas gift.
The Royal Mint says:
"As each calendar window is prised open by eager hands, the big day gets closer and closer. It’s almost time to choose a tree together, wrestle it through the front door and fetch the decorations down from the loft. Wrapped in tinsel, strung with lights and baubles hanging from every branch, the darkest time of the year is transformed into the most magical.
This year’s Royal Mint Christmas coin celebrates the very heart of our Yuletide traditions with this original Christmas tree design - the perfect way to remember a wonderful time spent with family and friends. Think wise men bearing gifts, a little extra for those who work hard all year, or a bag of chocolate treasure; Christmas and coins go hand-in-hand.
This year, tuck a real coin in their stocking. Keep the spirit of the season alive with this year-dated Brilliant Uncirculated £5 Christmas tree coin. Printmaker Edwina Ellis captures the excitement of the festive season through the stars, baubles and candy canes that deck the branches of the tree - the centrepiece of any home at Christmas."
The coins come in a presentation folder, Royal Mint Product Code: UK17CTBU, issue price: £13.00. | 
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