Definition
Champ de Mars (from the Latin Campus Martii, "Field of Mars") refers to the national assembly of the Frankish people, held annually in the month of March, in the open air. Under the early Merovingian and Carolingian kingdoms, this gathering served as the primary deliberative and military review body of the Frankish realm — a convocation of free warriors and nobles convened by the king to review troops, receive tribute, declare war, and issue legislative decrees. The assembly gave the month of March both its symbolic and practical significance in early medieval governance.
Common Language
Modern common usage (Wiktionary): Champ de Mars is widely recognized as a large public greenspace in Paris, France, located near the Eiffel Tower; also used generically for parade grounds or public fields named in honor of the Roman god Mars.
Historical common usage (Webster's 1913): "Champ de Mars" appears as a proper noun referring to the famous Parisian field used for public gatherings, military reviews, and revolutionary assemblies in French history.
The gap between common and legal meaning here is historical rather than doctrinal. The common reference is geographical — a Parisian landmark. The legal and constitutional-historical meaning is institutional — a specific organ of Frankish governance predating France as a political entity by several centuries. A researcher encountering the term in a legal dictionary or a treatise on feudal or constitutional history should not mistake it for a reference to the Paris location.
Why It Matters in Research
This term appears almost exclusively in legal dictionaries as a historical constitutional reference, not as a term with active doctrinal application. Researchers are most likely to encounter it in:
Feudal and constitutional history sources. Treatises on early medieval governance, the origins of representative assemblies, or the comparative history of parliamentary institutions will invoke Champ de Mars as an ancestor-concept for legislative bodies. Legal historians tracing the lineage of deliberative assemblies from the Germanic tribal councils through the English Parliament often pass through the Frankish assembly.
Transition to Champ de Mai. Under Charlemagne and his successors, the assembly was shifted from March to May and became known as the Champ de Mai (Campus Madii or Campus Maii). Researchers working in sources from different periods may encounter both terms referring to related but distinct institutions. Conflating them is a common error in older secondary literature.
Citation caution. Burrill's entry cites "1 Rob. Ch. V. ub. sup." — a reference to William Robertson's historical works on European history. This is a historiographical rather than strictly legal citation, flagging that Champ de Mars belongs more to constitutional history than to case law or statute. Researchers should treat it accordingly and not expect to find judicial interpretations of the term.
Corpus connections. The term links outward to broader discussions of feudal tenure, the origins of representative government, and the distinction between Merovingian and Carolingian constitutional arrangements. In Law Mind materials, it will appear most often as background context in entries on feudalism, Germanic law, and the development of legislative assemblies.
Historical Dictionary Support
Black's (1st ed.), Black's (2nd ed.), and Burrill agree on the core definition: the national assembly of the Franks, held in March, in the open air. The Latin equivalents given vary slightly — Black's 1st offers Campus Martii, Black's 2nd gives Campus Martii (with a typographical artifact in the source), and Burrill provides the fullest treatment, identifying the assembly as held "in the month of March, in the open air" and grounding it in Robertson's historical account.
What the historical dictionaries do not address: the transition from Champ de Mars to Champ de Mai under the Carolingians; the substantive functions of the assembly (military review, legislative promulgation, tribute); or the assembly's relationship to later representative institutions. These sources treat the term as a gloss rather than a developed entry, which is appropriate given its limited operational significance in common law practice.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Feudal System; Origins of Representative Assemblies; Carolingian Law.