Definition
A historical category of English law referring to causes of action, disputes, and injuries cognizable before the Court of Chivalry (also called the court military) and, by extension, matters falling within the disciplinary and contractual jurisdiction of military tribunals. The term encompassed two broad classes of subject matter:
1. Matters of honor and armorial right — disputes over coats of arms, precedence, and questions of chivalric conduct tried before the Court of Chivalry as a civil jurisdiction.
2. Military discipline and service — matters concerning the governance, contracts, and conduct of soldiers and armies, including what today would be called courts-martial jurisdiction.
The term is not in active use in modern American or English law. It survives as a historical descriptor for the pre-modern division of legal jurisdiction that placed certain military, chivalric, and martial matters outside the ordinary common law courts.
Common Confusion
MILITARY CAUSES vs. COURTS-MARTIAL: These are not synonymous. Military causes described a category of subject matter and jurisdictional competence. Courts-martial are the institutional tribunals that adjudicate one subset of that subject matter — military discipline and criminal conduct by service members. The Court of Chivalry handled a different and older layer of military causes involving heraldry, honor disputes, and armorial rights, and had no criminal jurisdiction in the modern sense. Researchers encountering "military causes" in historical texts should not assume the term refers exclusively to courts-martial proceedings.
MILITARY CAUSES vs. MILITARY COURTS: Related but distinct. Military causes defines what is to be adjudicated; military courts defines where. Burrill and Rapalje treat these as companion concepts, and Blackstone organizes them adjacently in Book III, but they are analytically separable.
Why It Matters in Research
The term operates almost exclusively in historical English legal sources, primarily as a jurisdictional classification found in Blackstone and the institutional writers who follow him. Researchers working in pre-twentieth-century common law materials — particularly materials touching on heraldry, feudal tenure, military contracts, or the jurisdiction of prerogative courts — will encounter "military causes" as a structural label rather than a substantive doctrine.
Several navigational points deserve attention:
First, the term bridges two very different institutional histories. The Court of Chivalry (also called the Earl Marshal's Court) was a civil tribunal of ancient origin that by the seventeenth century had largely fallen dormant, while courts-martial were a developing and increasingly codified form of military criminal jurisdiction. Blackstone treats them together under the heading of "military causes" for organizational convenience, but their doctrinal histories diverge sharply. A researcher following the courts-martial thread will move into statutory military law; a researcher following the chivalric thread will move into prerogative jurisdiction and heraldic law.
Second, American legal materials have essentially no use for the category. The United States military justice system developed along its own statutory track — beginning with the Articles of War — without inheriting the Court of Chivalry's jurisdiction, which had no American counterpart. The Uniform Code of Military Justice governs modern U.S. military law entirely. When "military causes" appears in American legal dictionaries, it is reported as a matter of English legal history, not as operative American doctrine.
Third, the term may appear incidentally in older treatises on feudal tenure. Rapalje & Lawrence's reference to "military feuds" in the same definitional cluster signals that some sources treat military causes, military courts, and military tenures as a family of concepts. Researchers should track which branch of that family a given source is actually discussing.
Historical Dictionary Support
The three source dictionaries are in close agreement on the core definition, all tracing the term to the same passage in Blackstone's Commentaries, Book III, chapter 5. Black's and Burrill offer nearly identical formulations, both citing 3 Bl. Comm. 103 directly. Rapalje & Lawrence expand slightly, noting that "all matters concerning the discipline of the army, and contracts, &c., relating to deeds of arms and war" fall within the category — a formulation that usefully distinguishes the disciplinary from the honorific dimensions of the jurisdiction.
None of the source dictionaries address the American legal context, which is appropriate given that the term has no operative American application. What the historical dictionaries collectively miss is the subsequent divergence of the two institutional threads: by the time these dictionaries were compiled, the Court of Chivalry had been functionally extinct for generations, and courts-martial had become a distinct and heavily regulated institution. The historical dictionaries preserve the Blackstonian snapshot without tracking what happened to each branch.
Burrill's entry is notable for running military causes, military courts, and military feuds as consecutive headings — suggesting that nineteenth-century legal lexicography treated these as an integrated cluster of obsolescent English law concepts rather than as separately developed doctrines.
Jurisdictional Note
The term is a creature of English legal history with no direct American doctrinal equivalent. In England, the Court of Chivalry last sat in 1954 (Manchester Corporation v. Manchester Palace of Varieties Ltd.) for heraldic matters, but military discipline has been governed by statute for centuries. In the United States, military justice is governed exclusively by the Uniform Code of Military Justice and its implementing regulations; the category of "military causes" as a jurisdictional concept never took root in American law.
Encyclopedia Cross-Reference
The Law Mind Military, Veterans & Admiralty Law Encyclopedia: Military Rules of Evidence and the Military Judge's Role (military_9) — for the modern institutional framework that developed from the historical courts-martial branch of military causes.