The sovereign is a gold coin of the United Kingdom with a nominal value of one pound sterling, so a quarter sovereign is denominated as having £0.25 (twenty-five pence) in face value. Struck from 1817 until the present time, the sovereign was originally a circulating coin (see pre-decimal Sovereign) accepted in Britain and elsewhere in the world; it is now a bullion coin not intended for circulation, the intrinsic value of which is much higher than its face value.
In most recent years, it has borne on the reverse Benedetto Pistrucci's design of Saint George and the Dragon, created in 1817.
The Royal Mint issues several denominations of the Sovereign: Five Sovereigns (Quintuple Sovereign, five pounds gold), Double Sovereign, Full Sovereign, Half Sovereign and Quarter Sovereign; the quarter is the most recent addition to the range, having been issued only since 2009. Their designs are identical, as - according to tradition - this type of coin has never had its value and denomination spelled out anywhere on the coin. The various denominations are only distinguished by size and weight, these being exactly in proportion to their face value. Since 1817, the composition has always been 22 carat (91.67%) gold.
To celebrate the 90th birthday of Queen Elizabeth II, the Royal Mint issued a range of coins in 2016 carrying her special commemorative portrait by British sculptor James Butler which was first issued the previous year for coins commemorating the Queen as the Longest Reigning Monarch in British history. In the portrait, the Queen is wearing the George IV State Diadem which also features in the definitive portraits by Jody Clark and Raphael Maklouf.
These coins were issued in Proof FDC grade only, separately boxed or in sets. | 
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