The livre was the currency of France until 1795. Several different livres existed, some concurrently. The livre was the name of both units of account and coins.
The livre was established by Charlemagne as a unit of account equal to one pound of silver. It was subdivided into 20 sous (also sols), each of 12 deniers. The word livre came from the Latin word libra, a Roman unit of weight. This division is also seen in the old English pound sterling, which was divided into 20 shillings, each divided into 12 pence.
This first livre is known as the livre carolienne. Only deniers were initially minted but debasement led to larger denominations being issued. Different mints in different regions used different weights for the denier leading to several distinct livres of different values.
Upon his return from the crusades, Louis IX instigated a royal monopoly on the minting of coinage in France and minted the first gold écu d'or and silver gros d'argent, whose weights (and thus monetary divisions) were roughly equivalent to the livre tournois and the denier.
Between 1360 and 1641, coins worth 1 livre tournois were minted known as francs. This name persisted in common parlance for 1 livre tournois but was not used on coins or paper money.
The official use of the livre tournois accounting unit in all contracts in France was legislated in 1549. However, in 1577, the livre tournois accounting unit was officially abolished and replaced by the écu, which was at that time the major French gold coin in actual circulation. In 1602, the livre tournois accounting unit was brought back.
Louis XIII of France stopped minting the franc in 1641, replacing it with coins based on the silver écu and gold Louis d'or. The écu and Louis d'or fluctuated in value, with the écu varying between five and six livres tournois until 1726 when it was fixed at six livres.
In 1667, the livre parisis was officially abolished. However, the sole remaining livre was still frequently referred to as the livre tournois until its demise.
The first French paper money was issued in 1701 and was denominated in livres tournois. However, the notes did not hold their value relative to silver due to massive over–production. The Banque Royale (the last issuer of these early notes) crashed in 1720, rendering the banknotes worthless (see John Law for more on this system).
In 1726, under Louis XV's minister Cardinal Fleury, a system of monetary stability was put in place. Eight ounces (a mark) of gold was worth 740 livres, 9 sols; 8 ounces of silver was worth 51 livres, 2 sols, 3 deniers. This led to a strict conversion rate between gold and silver (14.487 to 1) and established the values of the coins in circulation in France at:
A coin of value 1 livre was not, however, minted.
Paper money was reintroduced by the Caisse d'Escompte in 1776, denominated in livres. These were issued until 1793, alongside assignats from 1789. Assignats were backed (in theory) by government-held land. Like the issues of the Banque Royale, their value plummeted.
The last coins and notes of the livre currency system were issued in the Year II of the Republic (1794). In 1795, the franc was introduced, worth 1 livres 3 deniers.
The livre had also been used as the legal currency of the Channel Islands. The Jersey livre remained legal currency in Jersey until 1834 when dwindling supplies of no-longer minted coins obliged the adoption of the pound as legal tender.
Today, the Basque language calls the French franc the libera.
The livre at the time of its replacement by the franc was worth, in today's money, about £2.5 or $4 per livre.