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.
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 half sovereign is a continuation of the pre-decimal half sovereign, and has been issued as a decimal coin since 1980.
The designs of all denominations 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.
In most recent years, the reverse has had Benedetto Pistrucci's design of Saint George and the Dragon; from time to time though - starting in 1989 - the Royal Mint issues one year type coins with different designs, as a celebration for major events (usually Royal in nature). | 
