Pounds, shillings and pence

£sd (occasionally written Lsd) is the popular name for the pre-decimal currencies once common throughout Europe, especially in the British Isles and hence in several countries of the British Empire and subsequently the Commonwealth. The abbreviation originates from the Latin currency denominations librae, solidi, and denarii. In the United Kingdom, which was one of the last to abandon the system, these were referred to as pounds, shillings, and pence (pence being the plural of penny). When spoken it was pronounced "ell-ess-dee", or more commonly "pounds, shillings and pence".

This system originated in the classical Roman Empire. It was re-introduced into Western Europe by Charlemagne, and was the standard for many centuries across the continent. In Britain it was King Offa of Mercia who adopted the Frankish silver standard of librae, solidi and denarii in the late 8th century, and the system was used in much of the British Commonwealth until the 1960s and 1970s, with Nigeria being the last to abandon it with the introduction of the naira on 1 January 1973.

Under this system, there were 12 pence in a shilling and 20 shillings, or 240 pence, in a pound. The penny was subdivided into 4 farthings until 31 December 1960, when they ceased to be legal tender in the UK, and until 31 July 1969 there were also halfpennies ("ha'pennies") in circulation. The advantage of such a system was its use in mental arithmetic, as it afforded many factors and hence fractions of a pound such as tenths, eighths, sixths and even sevenths and ninths if the guinea (worth 21 shillings) was used. When dealing with items in dozens, multiplication and division are straightforward; for example, if a dozen eggs cost four shillings, then each egg was priced at fourpence.

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