Guinea, a gold coin current in Great Britain from 1664 down to 1817, when it was superseded by the Sovereign (q.v.), was at first coined out of gold from the Guinea coast. It was designed to be of the value of twenty shillings, and as legal tender it had no higher value till 1718. But its actual value varied. Thus in 1695 it was as high as thirty shillings, in 1697 twenty-two shillings, thereafter till 1717 twenty-one and sixpence, but was finally fixed at twenty-one shillings. It is still customary in Great Britain to estimate professional fees, honoraria of all kinds, complimentary subscriptions, prices of pictures, race-horses, &c. in guineas. In 'spade guineas' the reverse bears a spade-shaped shield with the royal arms.