Definition
Latin. "By the king's license." A phrase denoting that an act, grant, or proceeding was undertaken with the express permission or authority of the crown. In medieval and early English law, certain acts — particularly those that might otherwise be unlawful or that touched royal prerogative — required formal royal license before they could be validly performed. Ex licentia regis signified that such license had been obtained, serving as a legal warrant for the act in question.
The phrase appears most prominently in the context of alienation of lands held in fee, certain ecclesiastical appointments, and the formation of corporate bodies, all of which historically required crown approval. A subject acting ex licentia regis was protected from the legal consequences that would otherwise attach to performing the act without permission.
Why It Matters in Research
This is a term of medieval and early modern English legal history with little operative force in contemporary law. Researchers will encounter it primarily in:
- Historical English sources covering feudal land tenure, particularly cases involving alienation in mortmain, licenses to alienate fee estates, and royal grants of privilege.
- Treatises and commentaries citing Bracton or Blackstone's Commentaries, where the phrase appears in discussions of crown prerogative and the king's control over the landholding system.
- Records from Chancery and other royal courts where licenses were formally enrolled.
The key research trap is treating the phrase as a mere formality. In its historical context, ex licentia regis carried real legal consequence: an act performed without the required royal license could be void, subject to forfeiture, or actionable by the crown. The presence or absence of the license was a substantive legal question, not a procedural nicety.
Researchers should also note the phrase's relationship to the broader system of royal prerogative licensing, which declined significantly after the Statute of Quia Emptores (1290) and the Statute of Mortmain, and was further eroded by later statutory reforms. By the time Blackstone wrote, references to the phrase were largely retrospective and doctrinal rather than practically operative.
Historical Dictionary Support
The three source dictionaries agree on the core meaning — "by the king's license" — but differ in what they provide around it.
Burrill gives the cleanest definition: "By the king's license," citing 1 Blackstone's Commentaries 168 note. This is the most accurate and serviceable entry.
Black's 1st edition introduces noise. Its entry reads "By the king's thing which consisted in number, weight, or license" — an apparent corruption or misprint that conflates ex licentia regis with another entry or garbles the definition. This rendering is not meaningful and should be disregarded. Researchers encountering this entry in the first edition should cross-check against Burrill and the second edition.
Black's 2nd edition corrects the first, offering "By the king's license" with the same Blackstone citation, and then immediately transitions to a separate entry for EX LOCATO — a structural artifact of dictionary formatting that should not be read as connected to ex licentia regis.
All three sources cite 1 Blackstone's Commentaries 168 note as the authority. Bracton and Reeve's History of English Law are cited in the first and second editions of Black's as additional historical sources, consistent with the phrase's origins in medieval legal doctrine.
None of the historical dictionaries provide substantive discussion of the contexts in which the license was required or the consequences of proceeding without it. Researchers seeking that analytical depth will need to go directly to Blackstone, Bracton, or secondary histories of English land law.
Jurisdictional Note
Ex licentia regis is a term of English legal history and has no direct operative equivalent in American law. U.S. legal sources will encounter it only in historical context, principally in discussions of English land tenure that inform American property law doctrine.