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.
Britannia as a symbol has been depicted on British coinage for centuries. The bullion series called Britannia has been issued in gold since 1987 and in silver since 1997; it has a "definitive" depiction - used on bullion coins (Brilliant Uncirculated grade), as well as “Britannia, the Changing Face of Britain” - a series of one-year designs like this one - used on proofs made for collectors.
The design for 2015 is the first commission of Antony Dufort for the Royal Mint; his interpretation of this much-loved national figure was so admired by the Mint that it was selected for the country’s new definitive bimetallic circulating £2 introduced the same year. The icon wears her familiar Corinthian helmet and holds the trident, a symbolic reminder of Britain’s maritime might. The version for the silver and gold proofs is given more details than the one on circulating coinage; there is a backdrop of a sailing ship with billowing sails, cliffs and a lighthouse - a nod to the pre-decimal penny and halfpenny designs. | 
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