Definition
A Latin phrase from medieval English law meaning "to join the duellum" — that is, to formally engage in trial by combat. The phrase describes the act of accepting and entering into judicial combat as a recognized mode of proof or dispute resolution. When parties to a legal controversy were ordered or consented to resolve their dispute by battle, jungere duellum referred to the moment of formal joinder in that combat, analogous to the joinder of issue in pleading.
Why It Matters in Research
This term is encountered almost exclusively in sources treating medieval English procedure and will not appear in modern legal materials. Researchers tracing the history of proof and adjudication — particularly the transition from archaic modes of trial (ordeal, combat, compurgation) to rational evidence systems — may encounter this phrase in treatises and Year Book commentary discussing the wager of battle. It signals a procedural moment: the formal commitment of both parties to resolve a matter through combat rather than through inquest or other means.
The phrase appears in Fleta, a late-thirteenth-century English legal treatise modeled on Bracton. Researchers using Fleta as a primary source should treat jungere duellum as a technical term of art specific to that procedural context, not a general expression. Because wager of battle survived formally in English law longer than is commonly assumed — it was not abolished by statute until 1819 — researchers examining legal history through that period may occasionally find references to the underlying institution, though the Latin phrase itself becomes archaic well before abolition.
Researchers should be aware that the procedural vocabulary surrounding trial by combat is scattered across multiple Latin and Law French sources. Jungere duellum is one piece of that vocabulary; related terms (see below) round out the framework. Modern secondary literature on the abolition of trial by combat is the more practical entry point for most researchers; the Latin phrase is primarily of value when working directly in medieval primary sources.
Historical Dictionary Support
All three source dictionaries — Black's (1st), Black's (2nd), and Burrill's — are in complete agreement, offering near-identical entries: the phrase is glossed as "to join the duellum; to engage in the combat," each citing Fleta, lib. 1, c. 21, § 10 as the sole authority. The uniformity across editions reflects that this is a narrow, archaic term with a single established meaning and a single traceable source. None of the dictionaries elaborates on the procedural significance of the phrase or its place within the broader mechanics of wager of battle. Burrill adds a note on "JUNIOR" immediately following, confirming the brevity of the treatment and suggesting the compilers viewed this as a term requiring only a glossing rather than substantive analysis.
The reliance on Fleta alone, without reference to Bracton, Glanvill, or Year Book materials, is a limitation researchers should note. Fleta is the immediate textual home of the phrase, but the institution it describes is treated at greater length elsewhere in the medieval legal literature. The dictionaries do not address the procedural steps preceding jungere duellum — the challenge, the wager, the formal pledges — which are necessary context for understanding what "joining" the combat meant as a legal act.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Trial by Combat; Wager of Battle; Medieval English Procedure