Coins of the pound sterling another silver coin, the sceat, of 20 troy grains weight, which was in general circulation in Europe during the Middle Ages. The weight of the English penny was fixed at troy grains (about 1.46 grams) by Offa of Mercia, an 8th-century contemporary of Charlemagne. The coin's designated value, however, was that of 24 troy grains of silver (one pennyweight, or of a troy pound, or about 1.56 grams), with the difference being a premium attached by virtue of the minting into coins. Thus, 240 pennyweights made one troy pound of silver in weight, and the monetary value of 240 pennies
Great Recoinage of 1816 shillings weighing 87.2727 grains (or 5.655 grams), half-crowns of 218.1818 grains (14.138 grams) and crowns of 436.3636 grains (28.276 grams). Over the many reigns until decimalisation other denominations came and went, such as the threepence, sixpence, florin, and double florin, always weighing exactly one troy pound per 66 shillings (irrespective of fineness, which was reduced to 50% in 1920, and to 0% in 1947). This made 5 sterling silver shillings (which is 1 crown), about the weight of .9091 troy ounce of sterling silver. Great Recoinage of 1816 The Great Recoinage of 1816 was an attempt by the British Government