The sovereign is a gold coin of the United Kingdom, with a nominal value of one pound sterling. Struck from 1817 until the present time, it 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. There are several denominations of the Sovereign: Five Sovereigns (Quintuple Sovereign, five pounds gold), Double Sovereign, Full Sovereign, Half Sovereign and Quarter Sovereign; the current double sovereign - with face value of £2 is a continuation of the pre-decimal double sovereign, and has been issued as a decimal coin since 1974.
Apart from the sovereigns of the United Kingdom, the British Overseas Territory of Saint Helena, Ascension and Tristan da Cunha has also authorised some mints to issue double sovereigns under its jurisdiction. These are denominated in Saint Helena Pounds - the local variation of the Pound Sterling. Following long-standing tradition, this type of coin has never had its value and denomination spelled out anywhere on the coin.
The mint says about this coin:
Our Masterpiece Collection continues with this rare opportunity to own William Wyon’s stunning interpretation of the original design of St George and the Dragon.
In 1844 William Wyon was personally commissioned to design a medal for Queen Victoria’s husband, Prince Albert. Albert was a progressive thinker, an evangelist for technological progress, a supporter of human rights causes such as emancipation and, perhaps most famously, a patron of the Arts, becoming President of the Society of Arts in 1843 before it gained its royal charter in 1847.
During the 1840s the Society of Arts held popular annual exhibitions that showcased British ingenuity. Henry Cole, a Society member, came up with the idea of a "Great Exhibition" which would celebrate such brilliance from across the globe. Prince Albert became President of the Royal Commission for the Exhibition of 1851, calming concerns from Parliament with his belief that the event would place British creativity and engineering on the world stage.
The Great Exhibition proved to be a spectacular success and, in tribute to his achievements and as “a token of remembrance of our long communion in this work”, Prince Albert presented Henry Cole with the special medal he had personally commissioned from William Wyon.
Wyon’s interpretation of St George and the Dragon, an iconic image that has become synonymous with his early rival, Benedetto Pistrucci (who designed the famous Saint George and the Dragon sovereign), is full of energy as St George slays the mighty dragon beneath his rearing steed, believed to have been modelled upon Prince Albert’s favourite horse, Imaun. | 
Search for Saint Helena: Double Sovereign 2023 Saint George and the Dragon on eBay 