Like many other mints, the Royal Mint issues bullion coins in precious metals, having much higher intrinsic value than their face value. The five ounce (5 oz) silver coins are denominated as ten pounds (£10).
The coins are legal tender but are not intended for circulation. They are targeted at bullion investors or collectors who appreciate the special editions as pieces of art. The coins are typically "one-year" types usually issued in parallel with smaller denominations with the same reverse designs.
This commemorative five ounces silver coin celebrates the Longest Reigning Monarch in the history of United Kingdom. On 9 September 2015 Queen Elizabeth II had ruled for more than 63 years and 216 days, which was the longest reign before her - that of Queen Victoria.
Excluding the £20, all the coins in the Longest Reigning Monarch coin range feature a new commemorative portrait by James Butler, which makes the coin a modern rarity, as it is unusual to have a portrait different from the "definitive" effigy of the monarch. | 
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