Definition
Latin: "found." A participial term appearing in two distinct legal phrases with separate legal significance:
1. Thesaurus inventus — treasure found, the Latin designation for treasure-trove: money, coin, gold, silver, or bullion discovered concealed in the earth or in some private place, the owner being unknown. The phrase identifies the subject matter of a specialized branch of property law governing who holds title to such discovered wealth.
2. Non est inventus — "he is not found." A return made by a sheriff or other officer upon a writ when the defendant or person named could not be located within the officer's jurisdiction. The phrase appears as a formal notation on process and is the operative statement triggering procedural consequences, including the issuance of further process or, in some historical contexts, outlawry proceedings.
Common Confusion
The two phrases in which inventus appears are operationally unrelated and should not be confused simply because they share the same Latin root. A researcher encountering inventus in a property or probate context is almost certainly dealing with thesaurus inventus and treasure-trove doctrine. A researcher encountering inventus in pleading records, process returns, or sheriff's returns is dealing with non est inventus and service-of-process procedure. Conflating the two contexts leads to misreading historical court records.
Why It Matters in Research
Inventus rarely appears as a standalone term in legal sources; it is almost always encountered as a component of one of its two established phrases. Researchers must therefore search under TREASURE-TROVE and NON EST INVENTUS as primary headings rather than under inventus itself — a point the historical dictionaries acknowledge implicitly by immediately redirecting to those entries.
For non est inventus: this phrase saturates early English and American court records, particularly in common law pleading materials, writs of capias, and sheriff's return books. In manuscript court records and printed plea rolls, the notation appears in abbreviated form (n.e.i. or non est inv.) and can easily be misread by researchers unfamiliar with the convention. The procedural consequences of a non est inventus return varied by writ type and evolved over time, so the phrase in a seventeenth-century record carries somewhat different procedural freight than the same phrase in a nineteenth-century American county court file.
For thesaurus inventus: the phrase anchors the English common law of treasure-trove, which vested found treasure in the Crown (or, in some grants, the lord of the manor) rather than the finder or landowner. American jurisdictions diverged sharply from this rule, generally rejecting the royal prerogative rationale. Researchers working across the Atlantic transition must be alert to this doctrinal fork: an English authority discussing thesaurus inventus may be entirely inapplicable in an American property dispute.
Corpus researchers should note that Anderson's sends the reader to FIND without elaboration, and Bouvier's sends to FOUND — both useful destination entries for the substantive property doctrine. Burrill's is the most instructive of the historical sources on the term itself, correctly identifying inventus as a participial form and providing both key phrases.
Historical Dictionary Support
The historical sources agree on the core definition — inventus means "found" — and uniformly present the same two illustrative phrases: thesaurus inventus and non est inventus. There is no meaningful divergence among Black's (both editions), Burrill's, Anderson's, and Bouvier's on this point.
Burrill's adds the most useful information of the group by tracing inventus to its parent verb invenire and flagging the old English law context. Black's (both editions) presents the definition identically across editions, suggesting no doctrinal evolution was perceived between the first and second editions on this point. Anderson's cross-reference to FIND and Bouvier's cross-reference to FOUND are structural redirections rather than substantive definitions; researchers should follow those cross-references for the developed property doctrine.
What the historical dictionaries do not address is the procedural mechanics of non est inventus returns — the consequences for service of process, subsequent writs, and the relationship to constructive service or substituted service developments. For that procedural dimension, researchers must move beyond the dictionary shelf to pleading treatises and practice manuals.
Jurisdictional Note
The treasure-trove doctrine embedded in thesaurus inventus was never uniformly adopted in the United States. Most American states vested title to found property in the landowner rather than the sovereign, departing from the English Crown-prerogative rule. The non est inventus return procedure, by contrast, was widely replicated in American common law practice but was progressively displaced by statutory substituted service regimes throughout the nineteenth and twentieth centuries.