Definition
A Latin term from old English law carrying two related but distinct meanings:
1. A tribute or exaction imposed by a feudal lord upon his vassals or tenants, typically levied to meet the lord's financial necessity. The term thus denoted a form of feudal taxation or extraordinary demand made by a superior on those holding land under him.
2. Molestation, trouble, hindrance, or vexation by suit — that is, the harassment or burdening of a person through legal proceedings or other interference with their affairs.
Both senses share a common thread: an imposition visited upon a subordinate, whether financial or procedural.
Common Confusion
The two meanings of occasio can mislead a researcher who encounters the term without context. In a feudal land tenure document, occasio almost certainly denotes the tribute sense. In a charter or statute concerning forest rights or personal liberty, it more likely carries the molestation or hindrance sense. Burrill draws the term specifically from forest law sources, which points toward the second meaning in that documentary context. Treating the two meanings as interchangeable produces significant interpretive error.
Why It Matters in Research
Occasio is a term confined almost entirely to medieval and early modern English legal sources. Researchers will not encounter it in modern case law or statutory material. Its primary habitat is feudal tenure records, forest charters, and Latin legal instruments from the Norman and Angevin periods onward.
Two research traps deserve attention. First, the word's surface resemblance to the ordinary Latin occasio (meaning "opportunity" or "occasion") can mislead a reader translating a medieval document without legal training. Neither sense of the legal term corresponds to the common Latin meaning. Second, the dual legal meaning requires close attention to document type: a feudal grant or roll is more likely using occasio in the tribute sense, while a charter of liberties or a forest proceeding is more likely using it in the molestation or vexation sense.
Burrill's citation to the Carta de Foresta (Charter of the Forest, 1217) is the most useful documentary anchor for the vexation sense. Researchers working with forest law materials — which generated a substantial body of medieval English legal text — should expect the molestation meaning. Barrington's Observations on the Statutes provides a secondary scholarly handle on the term's usage in that context.
For the tribute sense, the connection to feudal incidents and lord-tenant relations links occasio to the broader vocabulary of feudal exaction: tallage, aids, scutage, and related impositions. A researcher tracing the history of taxation or feudal obligations will find occasio sitting alongside those terms in primary sources and in historical legal dictionaries, though it is less commonly discussed than its relatives.
The term appears in all three shelf dictionaries with substantial agreement on both meanings. Its presence in Black's, Bouvier's, and Burrill's reflects its importance to nineteenth-century lawyers trained in common law history and required to interpret older instruments — a practical concern that has largely disappeared but remains essential for historians and legal archivists.
Historical Dictionary Support
Black's, Bouvier's, and Burrill's agree on both core meanings without material divergence. Bouvier adds "Burrill; Spel." as authorities, attributing the definition to Burrill and to Spelman's Glossarium — a standard reference for medieval Latin legal terms. Burrill himself cites Spelman directly, as well as the Carta de Foresta and Barrington's Observations on the Statutes.
Burrill's entry is the most precise: it explicitly situates the term in "old English law" and focuses on the molestation and hindrance meaning, grounding it in documentary sources rather than treating it as a floating definition. Black's includes the tribute meaning first and the vexation meaning second; Bouvier's reverses that priority. Neither Black's nor Bouvier's adds authority beyond what Burrill provides, suggesting both drew substantially from Burrill and Spelman.
No significant scholarly commentary exists in the modern period on occasio specifically. The historical dictionaries remain the primary analytical resource. Spelman's Glossarium, if accessible, would be the deepest source for further nuance.
Jurisdictional Note
Occasio is a term of English legal history. It does not appear in American, Scottish, or continental legal systems as a technical term of art. Researchers working in non-English medieval sources should treat any apparent cognate with caution, as usage may differ.