<P> The Royal Mint undertook a massive recoinage programme in 1816, with large quantities of gold and silver coin being minted . Previous issues of silver coinage had been irregular, and the previous issue, minted in 1787, did little to alleviate the chronic shortage of silver coinage in general circulation . New silver coinage was to be of . 925 (sterling) standard, with silver coins to be minted at 66 shillings to the pound weight . Hence, newly minted sixpences weighed 43.636 grains or 2.828 grams . </P> <P> The Royal Mint debased the silver coinage in 1920 from 92.5% silver to 50% silver . Sixpences of both alloys were minted that year . This debasement was done because of the rising price of silver around the world, and followed the global trend of elimination, or reduction in purity, of the silver in coinage . The minting of silver coinage of the pound sterling ceased completely in 1946 for similar reasons, exacerbated by the costs of the Second World War . New "silver" coinage was instead minted in cupronickel, an alloy of copper and nickel containing no silver at all . </P> <P> Beginning with Lord Wrottesley's proposals in the 1820s, there were various attempts to decimalise the pound sterling over the next century and a half . These attempts came to nothing significant until the 1960s when the need for a currency more suited to simple monetary calculations became pressing . The decision to decimalise was announced in 1966, with the pound to be divided into 100, rather than 240, pence . Decimal Day was set for 15 February 1971, and a whole range of new coins were introduced . Sixpences continued to be legal tender with a value of ​ 2 ⁄ new pence until 30 June 1980 . </P> <P> Sixpences issued during the reign of Edward VI feature a three - quarter portrait of the king on the obverse, with a Tudor rose to the left, and the denomination VI to the right . Surrounding the portrait is the inscription EDWARD VI DG AGL FRA Z HIB REX, or similar, meaning "Edward VI, by the Grace of God, King of England, France and Ireland". All sixpences minted under subsequent kings and queens bear a similar inscription on the obverse identifying the monarch (or Lord Protector during the Commonwealth), with the portrait usually flipping left - facing to right - facing or vice versa between monarchs . The reverse features the escutcheon of the Royal Arms of England, surrounded by the inscription POSVI DEVM ADIVTORE MEVM, or a variant, meaning "I have made God my helper". </P>

When did the silver sixpence go out of circulation