Definition
Designatio justiciariorum is a Latin maxim of medieval English legal procedure meaning, literally, "the designation of justices." It refers to the formal act or instrument by which justices were appointed, named, or assigned to a particular court, commission, or judicial function by royal authority. In the structure of early English law, judicial power did not vest automatically in an office but required specific royal designation — the naming of particular individuals to exercise jurisdiction in a given matter or territory. The maxim captures both the act of appointment and the legal significance of that act as the source of a court's or commissioner's authority to hear and determine causes.
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Why It Matters in Research
This is a term researchers will encounter almost exclusively in medieval and early modern English legal sources — writs, patent rolls, commissions of oyer and terminer, and treatises on the organization of royal justice. Its practical significance lies in understanding how jurisdiction was constituted in early English courts: jurisdiction was personal and commission-based, not structural in the modern sense. A court of justices in eyre, a commission of assize, or a special tribunal derived its authority not from a standing statute but from the designation itself. Challenging the designation — questioning whether the named justices had been properly appointed — was therefore a substantive legal objection, not a mere formality.
Researchers working in Law Mind's corpus on the history of English courts, royal commissions, or the development of judicial tenure should treat this term as a marker for questions about the source and limits of judicial authority rather than its substance. It connects directly to the broader doctrinal question of how jurisdiction was granted, transferred, and revoked under the common law before the modern statutory framework for courts was established.
Be alert to the fact that Black's 2nd Edition includes this entry in a context where surrounding text appears to concern desertion in military and maritime law — an artifact of the physical dictionary's page layout, not a substantive connection. The two topics are unrelated. Researchers consulting the print source or digitized scans should not read the surrounding material as contextually linked.
Historical sources vary in how rigorously they distinguish between the formal act of designation, the instrument recording it, and the legal effect of the designation on the court's jurisdiction. In some usages, designatio justiciariorum refers narrowly to the written commission; in others, it describes the entire administrative-legal process by which a justice received and exercised royal authority.
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Historical Dictionary Support
Black's Law Dictionary (2nd Ed.) provides the primary anglophone legal dictionary treatment of this term. The surrounding text in Black's, which references desertion law (In re Sutherland, 43 Fed. 531, and Hanson v. South Scituate, 115 Mass. 336), is unrelated editorial content from an adjacent entry and should be disregarded for purposes of understanding this term.
The historical dictionary record for designatio justiciariorum is thin in English-language legal dictionaries beyond Black's. The concept is more fully developed in Latin legal lexicons and in scholarly treatments of the English common law judiciary, including works on the eyres and assize system. Bracton's De Legibus et Consuetudinibus Angliae addresses the principle that justices act by royal commission, which is the doctrinal foundation this maxim encodes, though Bracton does not deploy the precise phrase as a term of art.
Later institutional writers, including Coke and Blackstone, treat the appointment and commission of judges as constitutive of their jurisdiction without necessarily foregrounding the Latin phrase. By the time of Blackstone's Commentaries, the concept had been largely absorbed into discussions of the crown's prerogative to constitute courts and commission judges, and the Latin maxim receded from active use.
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Jurisdictional Note
This term is specific to English legal history and the common law tradition derived from it. It has no direct equivalent in civil law systems, where the organization of courts proceeds on different constitutional and administrative foundations. American courts, organized by statute and constitution from the founding period, do not use this concept in any operative sense, though it may appear in historical scholarship on colonial-era court commissions.
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