Definition
FRANC carries two distinct legal meanings in historical Anglo-American legal sources:
1. Currency unit. A French silver coin and, from 1795 onward, the standard monetary unit of France. Historical legal dictionaries value it at approximately eighteen to twenty cents in American currency, reflecting exchange rates current at the time of publication. As a unit of account, the franc appears in contracts, treaty provisions, damage assessments, and commercial instruments involving French parties or French-law jurisdictions.
2. Free (adjective). In Law French and early legal usage, franc is an adjective meaning "free" — equivalent to the English "frank" in compound legal terms. It forms the root of several important feudal and property law concepts, most notably franc aleu (also spelled franc alleu or allodial land), denoting land held free of any feudal superior and exempt from seigniorial services and obligations. In this sense, franc does not name a coin but describes a quality of legal tenure.
Common Language
Modern common usage (Wiktionary): Any of several units of currency.
Historical common usage (Webster's 1913): A silver coin of France, and since 1795 the unit of the French monetary system, equivalent to about nineteen cents and divided into 100 centimes. Also adopted by Belgium and Switzerland.
The common meaning tracks only the currency sense, and even there the coin itself is obsolete — France adopted the euro in 2002. Researchers encountering franc in older legal instruments must determine from context whether the term is functioning as a currency denomination or as a freestanding adjective meaning "free," which is a distinctly legal usage invisible to ordinary English readers.
Common Confusion
The currency sense and the adjectival sense are historically unrelated in meaning and should not be conflated. A reader trained on modern English may assume all appearances of franc in legal documents refer to money; in fact, franc in compound terms like franc aleu, franc tenement, franc marriage, or franc garde functions purely as a modifier and carries no monetary meaning whatsoever. The confusion is compounded because both senses appear in the same historical legal corpora — French commercial law texts use franc as currency; feudal land-law texts use franc as a freedom qualifier.
Recognized Forms
/SUBTYPES
Franc aleu (franc alleu): Allodial land held entirely free of feudal tenure, owing no services or rents to a superior lord. Treated in French law and carried into Lower Canada. Distinguished from land held en fief, which was subject to seigniorial obligations.
Franc tenement: Free tenement; freehold. The adjectival franc modifying the tenure to indicate its free (non-villein) character.
Franc marriage (frankmarriage): A form of tenure in which land was granted in fee tail to a couple and the heirs of their bodies, held free of service during the lives of the original grantees and their first-generation heirs.
Why It Matters in Research
Disambiguation is the central research challenge. A source index entry for franc will not distinguish between the currency sense and the adjectival sense, and both appear throughout the Law Mind corpus. When researching commercial or admiralty matters involving French parties in the eighteenth and nineteenth centuries, franc is a monetary unit whose exact value depended on exchange rates variable across decades — do not assume the eighteen- to twenty-cent valuations in Black's and Bouvier's are interchangeable with rates operative in specific years or transactions.
When researching feudal tenure, Canadian seigniorial law, or French property law, franc as adjective is the operative meaning. The compound terms built on franc — franc aleu, franc tenement, franc marriage — each have independent doctrinal significance and separate dictionary entries in the historical sources. A researcher tracing the reception of French land tenure in Lower Canada (Quebec) must be alert to franc aleu as a technical term of art that persisted in Canadian legal usage long after it had become archaic in metropolitan French law.
Burrill gives the most guidance on the adjectival sense, directing researchers to the cognate entries Frank, Fraunc, and Fraunche. Black's and Bouvier's limit themselves to the coin, which reflects the period in which general-purpose legal dictionaries were less focused on feudal terminology. Researchers relying solely on Black's will miss the adjectival dimension entirely.
Historical Dictionary Support
The three source dictionaries diverge by focus rather than contradiction. Black's and Bouvier's treat franc exclusively as a currency denomination, differing only marginally on valuation (Black's: "a little over eighteen cents"; Bouvier's: "about twenty cents") — a discrepancy attributable to different edition dates and exchange rate fluctuations rather than doctrinal disagreement. Neither source engages the adjectival sense at all.
Burrill takes the opposite approach, treating franc primarily as the Law French adjective meaning "free" and directing readers to related entries, while addressing franc aleu at length with citations to Argou's Institutions au Droit Français and Kent's Commentaries. Burrill's entry is the most useful for property and feudal law research. The historical dictionaries collectively cover the term's range, but no single source covers both dimensions — a researcher must triangulate across all three.
Jurisdictional Note
The franc as currency is relevant primarily to transactions and instruments governed by French law, Belgian law, or Swiss law, and to admiralty and commercial cases involving those jurisdictions. The franc as adjective and its compound terms (particularly franc aleu) are significant in Quebec private law research, where French seigniorial tenure concepts remained operative under the civil law system well into the nineteenth century before seigniorial tenure was formally abolished.