By 1980 it had become apparent that with the general decline in purchasing power, the £1 unit of currency was more appropriate to a coin than a banknote. After consultation with many groups including retailers and special interest groups, the Government announced on 31 July 1981 that a new £1 coin that was to be issued on 21 April 1983. Since its launch the £1 has always represented the United Kingdom and its constituent parts; England, Wales, Scotland and Northern Ireland.
The £1 coin in base metal (as opposed to the gold sovereign, which has a nominal face value of one pound too), nickel-brass was introduced in 1983, as a replacement for the £1 banknote. The reverse design of the first £1 coin showed a detailed and intricate depiction of the Royal Coat of Arms. Designed by Eric Sewell, Chief Engraver at The Royal Mint, it has become one of the most famous images on British coinage. The coin’s edge inscription is in Latin: DECUS ET TUTAMEN, which may be translated as an "ornament to safeguard".
This design, representing the United Kingdom as a whole, was issued until 2008 with no change, then with a re-design in 2015, in rotation with other designs representing England, Scotland, Wales and Northern Ireland, alternating each year. With the introduction of Matthew Dent's new design of all circulating British coins, the United Kingdom was later represented by the Shield of the Royal Arms one pound coins.
The coin is made of Nickel-Brass, with composition of 70% copper, 5.5% nickel and 24.5% zinc.
These coins circulated until 2017, when they were demonetised and replaced with the current bimetallic one pound coin.
The reverse of the coin depicts the Royal Arms of the United Kingdom. In its standard variant used outside of Scotland, the shield is quartered, depicting in the first and fourth quarters the three passant guardant lions of England; in the second, the rampant lion and double tressure flory-counterflory of Scotland; and in the third, a harp for Ireland. The crest is a statant guardant lion wearing St Edward's Crown, himself on another representation of that crown standing on a knight's helmet.
The dexter (right) supporter is a likewise crowned English lion; the sinister (left), a Scottish unicorn. In the ground below, a thistle, Tudor rose and shamrock are depicted, representing Scotland, England and Ireland respectively.
The motto of English monarchs, DIEU ET MON DROIT (God and my Right), which has descended to the present royal family, is in a ribbon below, while a Garter circlet which surrounds the shield is inscribed with the Order of the Garter's motto, HONI SOIT QUI MAL Y PENSE (from old French: Shame on he who thinks evil).
Around below is the denomination, ONE POUND.