Imperial and US customary measurement systems in 1824, to take effect in 1826) and United States customary units which evolved from English Units from 1776 onwards. The earliest records of English units of measure involve the weight (and therefore the value) of Saxon coins. The penny introduced by Offa was about 20 grains (1.296 g). Edward the Elder increased the weight of the English penny to 26 grains (1.685 g), thereby aligning it with the penny of Charlemagne. By the time of the Norman Conquest (1066), it had decreased to 24 grains (1.555 g). This value was subsequently called the "pennyweight" and formed the basis of
Troy weight "troni" refers to markets. Watson finds the dialect word "troi", meaning a balance in Wright's Dialect Dictionary. Troy weight referred to the tower system; the earliest reference to the modern troy weights is in 1414. Many aspects of the troy weight system were indirectly derived from the Roman monetary system. The Romans used bronze bars of varying weights as currency. An ("heavy bronze") weighed one pound. One twelfth of an was called an , or in English, an "ounce". Before the adoption of the metric system, many systems of troy weights were in use in various parts of Europe, among