page_title: Pound (mass)
section_title: Tower pound
hierarchical_section_title: Pound (mass) / Historic use / In Britain / Tower pound
caption_attribution_description: English: The Pound&#160;! A Pound = 20 shillings = 240 silver pennies [Old Calculations]
context_page_description: The pound or pound-mass is a unit of mass
  used in the imperial, United States customary and other systems of measurement. Various definitions have been used; the most common today is the international avoirdupois pound, which is legally defined as exactly 0.45359237 kilograms, and which is divided into 16 avoirdupois ounces. The international standard symbol for the avoirdupois pound is lb; an alternative symbol is lbₘ, #, and ℔ or ″̶.
  The unit is descended from the Roman libra. The English word pound is cognate with, among others, German Pfund, Dutch pond, and Swedish pund. All ultimately derive from a borrowing into Proto-Germanic of the Latin expression lībra pondō, in which the word pondō is the ablative case of the Latin noun pondus.
  Usage of the unqualified term pound reflects the historical conflation of mass and weight. This accounts for the modern distinguishing terms pound-mass and pound-force.
context_section_description: The system called Tower weight was the more general name for King Offa's pound. This dates to 757 AD and was based on the silver penny. This in turn was struck over Arabic dirhams (2d). The pound was based on the weight of 120 Arabic silver dirhams, which have been found in Offa's Dyke. The same coin weight was used throughout the Hanseatic League.
  The Tower pound was also called the Moneyers' Pound (referring to the Saxon moneyers before the Conquest), the easterling pound, which may refer to traders of eastern Germany, or to traders on the shore of the eastern Baltic sea, or dealers of Asiatic goods who settled at the Steelyard wharf; and the Rochelle Pound by French writers, because it was also in use at Rochelle. An almost identical weight was employed by the Germans for weighing gold and silver.
  The mercantile pound (1304) of 6750 troy grains, or 9600 Tower grains, derives from this pound, as 25 shilling-weights or 15 Tower ounces, for general commercial use. Multiple pounds based on the same ounce were quite common. In much of Europe, the apothecaries' and commercial pounds were different numbers of the same ounce. 
  The Tower system was referenced to a standard prototype found in the Tower of London and ran concurrently with the avoirdupois and troy systems until the reign of Henry VIII, when a royal proclamation dated 1526 required that the troy pound to be used for mint purposes instead of the Tower pound. No standards of the Tower pound are known to have survived.
  The Tower pound was equivalent to about 350 grams.
caption: The Tower pound
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