There were some gold coins of the early Saxon kings. Under the early Norman kings foreign gold coins were current, but the first regular gold coinage was that of Edward III; his Noble of fine gold, 1/50 of a Tower pound, weighed 108 grains, the weight of two golden florins of Florence or of two ducats or zechins of Venice. He afterwards coined nobles at the rate of 42 to the mint-pound; these weighed 119 grains, and, as they were of 23-7/8 carats fine, contained almost exactly the same weight of pure gold as the modern sovereign of 123-1/4 grains. Their value was about half a marc or 80 sterlings of full weight, and as the proper weight of silver in English coins was then three times that at present, the 6_s._ 8_d._ equivalence of the noble then is that of the sovereign now.
The weight of gold coins mattered little in practice; they were always weighed, and represented an amount of sterling varying according to the state of the money-market and to the condition of the silver coinage.
Edward IV’s noble was called a Rial; and the Angel, 2/3 of its weight or about 80 grains, was also coined. Henry VII coined a double Rial of half a Troy ounce. Under Henry VIII this was called a Sovereign.
The fineness of gold coins, originally of 23 carats 3-1/2 grains = 994·7 gold in 1000, was reduced to 22 carats under Henry VIII and, after some variations, this standard = 916·6 gold in 1000 was finally adopted.[36]
‘Twenty-four carat’ was taken as the standard of pure gold because the Roman gold solidus weighed twenty-four carats (each 1/144 of an ounce). The assayer’s carat is 1/24 part divided into four assay-grains. Medieval gold coins such as Edward III’s noble and the Venetian zechin, always of the same quaint pattern, were generally twenty-three carat 3-1/2 grains fine, = 995 parts in 1000. But this nearly pure gold being very soft, it became customary to alloy the metal with a certain amount of copper to give it the hardness necessary for trade purposes in modern times.
Sovereigns or Unites were coined under James I at 172 grains, under Charles I at 141 grains. Their value in silver varied of course according to market-rates for gold. Coined under Charles II at 130 grains they were henceforth called Guineas, varying in value from 30 to 20 shillings. Repeated attempts to fix their value by law utterly failed. In the eighteenth century it was generally above the 21_s._ standard at which the guinea is still reckoned as a polite coin. In 1816, on the adoption of a gold standard, the name of Sovereign was revived for the coin which is its basis.