Definition
Vadiare legem is a Latin phrase from medieval English law meaning "to wage law" — that is, to formally pledge or give security (a "gage") that one will appear on an appointed day to perform wager of law. The act of vadiare legem was the initiating step in the procedural defense known as wager of law (or compurgation), by which a defendant in a civil action pledged to return to court and swear an oath of innocence, supported by a requisite number of oath-helpers (compurgators) who would swear to the credibility of his oath. The phrase breaks into its operative parts: vadiari, to give a pledge or gage, and legem, the law or oath to be made. Together they describe the formal entry of a defendant into the compurgation process. Once law was waged (vadiata lege), the court assigned a future day on which the defendant would actually make his law — that is, complete the sworn denial.
Common Confusion
Vadiare legem (to wage law) is sometimes collapsed with facere legem (to make law) in casual reading of medieval sources. They are distinct procedural moments: vadiare legem is the pledge or security given at the outset that the defendant will appear and perform; facere legem is the actual performance — the completed oath with compurgators on the appointed day. Burrill's entry captures both stages: "was admitted to wage and make his law" describes the full arc, but the two acts were temporally and procedurally separate. Researchers reading plea rolls or register entries should be alert to which stage is being recorded.
Why It Matters in Research
This term appears almost exclusively in pre-modern English legal sources — Glanvill, Bracton, Fleta, and the Registers of Original Writs — and will not be encountered in modern case law or statutes. Its significance is entirely historical and procedural.
For corpus researchers, several traps arise. First, vadiare legem is tightly bound to the wager of law procedure, which was formally abolished in England by statute in 1833. Any document using this phrase therefore predates or discusses pre-abolition practice; its presence is a reliable dating and procedural signal. Second, the term appears in highly abbreviated Latin in plea rolls and registers, and scribal contractions can obscure whether a record describes the pledge stage or the completion stage. Third, American legal materials rarely use this phrase at all — wager of law never took firm root in colonial American practice and was effectively dead as a living procedure well before independence — so researchers encountering it in American sources are almost certainly reading historical commentary or reception history, not live procedural records.
The phrase also connects to a cluster of related Latin procedural terms (vadium, lex, legem facere, compurgatio) that appear throughout Bracton and Fleta. Understanding vadiare legem unlocks the surrounding vocabulary and helps researchers parse the full compurgation sequence in those treatises.
Historical Dictionary Support
Burrill's Law Dictionary is the primary English-language historical source capturing this term with precision. Burrill correctly identifies it as a term of old English law, correctly distinguishes the pledge stage from the performance stage, and cites the authoritative medieval sources: Glanvill (lib. 1, c. 9), Bracton (fol. 156b), Fleta (lib. 2, c. 44, § 2), Spelman's Glossarium, and the Registrum Omnium Brevium. These citations are reliable anchors for primary source research.
What Burrill does not do — and what researchers should not expect from any single historical dictionary entry — is situate vadiare legem within the broader decline and abolition of wager of law, or note its absence from American practice. The entry treats the term as a piece of Latin procedural vocabulary to be translated and sourced, which it accomplishes competently. Researchers needing the institutional history of compurgation will need to move beyond the dictionary to treatise literature.
No meaningful divergence exists among historical dictionaries on this term; it is narrow enough that sources which define it at all tend to agree. The primary risk is not conflicting definitions but the absence of the term in shorter or later reference works that had already consigned wager of law to antiquarian history.
Jurisdictional Note
Vadiare legem is a term of English medieval common law. It has no equivalent procedural life in American jurisdictions, which generally did not adopt wager of law as an operative defense. Researchers working in Scottish, civilian, or canon law sources will encounter compurgation under different terminology entirely.