Definition
Lettre (also lettre, Law French) is a term appearing in French law and old English law to denote a formal written instrument conferring authority. The word functions as the French and Law French equivalent of the English "letter" but carries, in legal contexts, the specific sense of an official document — not casual correspondence.
The term appears in legal sources in several overlapping senses:
1. A formal grant or conveyance. In old English practice, lettre referred to an instrument conveying or granting rights, taking its name from the written form through which the transaction was accomplished. Burrill records the standard Law French opening formula: A toutz ceux que ceste lettre verrount ou orrount — "To all those who shall see or hear this letter" — a conventional preamble used in deeds and grants.
2. A writ. Burrill notes that lettre could also designate a writ in old English legal usage.
3. A written authority to an attorney. In early English practice, a lettre served as the written authorization constituting an attorney to act on a party's behalf.
4. A royal or governmental instrument (French law). In French law, lettre functioned as a general term for formal instruments issued under sovereign authority, most prominently in the compound lettres de cachet.
Common Language
Modern common usage (Wiktionary): Obsolete form of "letter."
Historical common usage (Webster's 1913): Not separately defined; lettre is treated as a French-language spelling variant of "letter."
In common usage, lettre is simply an archaic or foreign-language spelling with no independent meaning. The legal significance of the term lies entirely in the formal, authorizing character of the instruments it described — a distinction the common definition does not capture. A researcher encountering lettre in a legal source should not read it as mere correspondence; it signals a formal legal instrument with operative legal effect.
Recognized Forms
/SUBTYPES
Lettres de cachet. The most historically significant compound. These were instruments issued and signed by the kings of France, countersigned by a secretary of state, authorizing the imprisonment of a named individual without trial or formal charge. Black's 2nd edition attributes their origin to Père Joseph under Cardinal Richelieu's administration. Lettres de cachet became a symbol of arbitrary royal power and their abolition was among the early acts of the French Revolution. The phrase appears frequently in comparative constitutional discussions and in historical treatments of due process and liberty.
Why It Matters in Research
Lettre is a term researchers encounter primarily in two contexts: (1) medieval and early modern English legal materials written in Law French, and (2) discussions of pre-Revolutionary French law, especially in comparative or constitutional history.
In Law French sources, lettre often appears in opening formulae of deeds and grants. Readers unfamiliar with Law French conventions may misread these formulae as mere formalities rather than recognizing the operative legal text that follows. The Britton citations in Burrill (c. 40, 41, 120) indicate that lettre carried distinct technical senses — grant, writ, and attorney's authority — depending on context, and source documents rarely signal which sense is intended.
The lettres de cachet subtype carries outsized significance in constitutional and legal history research. It appears in Enlightenment critiques of despotism, in comparative discussions of habeas corpus and due process, and in treatments of the French Revolution's legal reforms. Researchers working in these areas should be alert to the term appearing in translated sources, where it may be rendered as "sealed letter," "royal letter," or simply "royal warrant."
Jurisdictional confusion is a live research trap: lettre in an English source carries Law French meaning rooted in medieval English practice; lettre in a French source belongs to French civil and public law traditions. The two streams are related but not identical, and the same word in different corpora can describe different instruments with different legal effects.
Historical Dictionary Support
All three source dictionaries converge on the basic definition — a formal written instrument giving authority — but they approach the term from different angles, reflecting their different scholarly purposes.
Black's (1st and 2nd editions) treat lettre primarily as a French law term and do not develop its English law dimensions. Both editions flag the parallel to English usage of "letter" as a formal instrument, which is a useful anchor for researchers approaching from common law sources.
Burrill adds substantially more texture, grounding lettre in old English law practice with specific references to Britton and a recorded formula. Burrill's entry is the most useful starting point for researchers working in medieval English materials, because it identifies all three distinct legal senses (conveyance, writ, attorney's authority) and provides a concrete textual example of the instrument in use.
Neither Black's edition engages meaningfully with the Law French dimension of the term in English sources; their framing is almost entirely French law. Burrill does not address lettres de cachet. Between the two, a complete picture of the term requires consulting both traditions.
Jurisdictional Note
In the common law tradition, lettre and its compounds appear primarily in English sources predating the displacement of Law French in the courts (effectively ended by statute in the mid-seventeenth century). In French law, derivatives of lettre remained in active legal use through the ancien régime. Modern French legal usage retains lettre in formal instruments but the historical legal senses are confined to historical materials.