text: As early as 1147 in Troyes in Champagne (in the Middle Ages an important trading town) a unit of weight called  was used.
  The national French standard until 1799 was based on a famous artifact called the , which probably dates back to the second half of the 15th century. It is an elaborate set of nesting weight pieces, with a total metric weight of 12.238 kg. The set is now shown in the Musée des Arts et Métiers in Paris. The total nominal value of the set is 50  or , a mark being 8 ounces. The ounce  had therefore a metric equivalent of 30.59 g. The  was used as a national French standard for trading, for gold, silver, and jewels, and for weighing medicine. It was also used in international communications between scientists. In the time before the French Revolution, the civil pound also played the role of the apothecaries pound in the French apothecaries system, which otherwise remained a standard system of the Romance (24 grains per scruple) type.
  In Bruges, Amsterdam, Antwerp and other Flemish cities, a "troy" unit ("") was also in use as a standard for valuable materials and medicine. As in France, the way in which the Flemish troy ounce was subdivided depended on what was weighed. Unlike the French, the Flemish apothecaries divided the scruple into 20 grains. The Flemish troy pound became the standard for the gold and apothecaries system in the United Kingdom of the Netherlands; it was also used in this way in Lübeck. (The London troy pound was referred to as the ', after metrification.)
  The Dutch troy mark consisted  of 8 Flemish troy ounces, with each ounce of 20 engels, and each engel divided into 32 assen. The Amsterdam Pound of two marks, used in commerce, weighed 10,280 assen, while the Amsterdam Troy pound weighed 10,240 assen, i.e. exactly two troy marks.
  In 1414, six years before the Treaty of Troyes, a statute of Henry V of England gave directions to the goldsmiths in terms of the troy pound. (In 1304 it had apparently not yet been introduced, since it did not appear in the statute of weights and measures.) There is evidence from the 15th century that the troy pound was used for weighing metals and spices. After the abolishment of the Tower pound in 1527 by Henry VIII of England, the troy pound was the official basis for English coin weights. The British apothecaries' system was based on the troy pound until metrication, and it survived in the United States and Australia well into the 20th century.
  Since the modern (English, American and Imperial) troy ounces are roughly 1.5% heavier than the late Paris ounce, the exact historical relations between the original , the French , the Flemish  and the English troy pound are unclear. It is known, however, that the numerical relation between the English and French troy ounces was exactly 64:63 in the 14th century.