Definition
In Roman and early civil law, to purge oneself of a criminal charge by means of a formal oath. The accused would swear to innocence, sometimes supported by oath-helpers or compurgators who attested to the accused's credibility. The term functioned as a procedural mechanism of self-purgation, offering an alternative to trial by ordeal or formal proof in certain contexts.
Common Confusion
Adlegare should not be confused with compurgation or wager of law, though the underlying logic is closely related. Compurgation is the broader practice of oath-based defense supported by oath-helpers; adlegare refers more specifically to the act of oath-purgation itself, particularly as framed in Roman and civil law sources. Researchers encountering the term in medieval ecclesiastical or civil law contexts may find it used loosely alongside compurgatio, but the two are not fully synonymous.
Why It Matters in Research
Adlegare is a term of narrow, archaic usage. Researchers will encounter it almost exclusively in sources dealing with Roman law, early medieval procedure, or ecclesiastical courts. It is absent from common law dictionaries because oath-purgation of this civil law variety did not transplant intact into English common law — though the functional parallel, wager of law, existed in common law under its own terminology.
The primary trap for corpus researchers is anachronism: adlegare belongs to a procedural world that had largely dissolved before modern legal systems formed. Sources using the term after the medieval period are almost certainly doing so in a historical or comparative law context, not as a live procedural reference. A researcher who finds adlegare in a 19th-century treatise should treat it as a term of legal history, not contemporary doctrine.
Connections within the Law Mind corpus run through Roman law materials, civil law commentaries, and ecclesiastical court procedure. Cross-referencing with compurgation and wager of law will recover the parallel common law and canonical developments that adlegare's civil law form sits beside.
Historical Dictionary Support
Rapalje & Lawrence give a compressed but accurate definition: "to purge one's self of crime by oath." This captures the essential meaning but provides no procedural context — no indication of when adlegare applied, what form the oath took, or how it related to other modes of proof. Historical dictionaries generally treat adlegare as a one-line entry, reflecting its status as a term of historical curiosity rather than active doctrine by the time legal dictionaries were being compiled in the 19th century. No significant divergence exists among historical sources because so few address the term at all; agreement by silence is the rule here. Researchers should not expect historical dictionaries to illuminate the procedural mechanics. For depth, civil law treatises and Roman law scholarship are the appropriate sources.