GUINEA  , a

gold coin at one time current in the United Kingdom . It was first coined in 1663, in the reign of Charles II., from gold imported from the Guinea coast of West Africa by a company of merchants trading under charter from the British crown—hence the name . Many of the first guineas bore an elephant on one side, this being the stamp of the company; in 1675 a castle was added . Issued at the same time as the guinea were five-guinea, two-guinea and half-guinea pieces . The current value of the guinea on its first issue was twenty shillings . It was subsidiary to the silver coinage, but this latter was in such an unsatisfactory state that the guinea in course of time became over-valued in relation to silver, so much so that in 1694 it had risen in value to thirty shillings . The rehabilitation of the silver coinage in William III.'s reign brought down the value of the guinea to 21s . 6d. in 1698, at which it stood until 1717, when its value was fixed at twenty-one shillings . This value the guinea retained until its disappearance from the coinage . It was last coined in 1813, and was superseded in 1817 by the present principal gold coin, the sovereign . In 1718 the quarter-guinea was first coined . The third-guinea was first struck in George III.'s reign (1787) .

To George III.'s reign also belongs the "

spade-guinea," a guinea having the shield on the reverse pointed at the base or spade-shaped . It is still customary to pay subscriptions, professional fees and honoraria of all kinds, in terms of " guineas," a guinea being twenty-one shillings .