Definition
Testamentum (Latin) is the Roman and early English legal term for a testament or will — a formal declaration of a person's wishes regarding the disposition of property made in contemplation of death. In classical Roman civil law, testamentum referred specifically to the will or last will of a deceased person, the instrument by which inheritance and legacy were governed under the ius civile.
In old English law, the term carried a broader meaning. Bracton used testamentum to describe a disposition of property made in anticipation of death, treating it as a species of donatio mortis causa — a gift conditioned on the donor's death. Beyond this, the term was applied as a general name for instruments of conveyance broadly, including deeds and charters. This broader usage derived either from the instrument's function as written testimony of a transaction or from its authentication by witnesses (testes), with the word testamentum sharing its root with testis (witness) and testari (to bear witness or make a will).
Common Confusion
Testamentum is sometimes read as a precise equivalent of the modern English "will" or "last will and testament," but the equivalence is imperfect in two directions. First, in Roman law, testamentum had formal requirements and a specific legal structure under the ius civile that do not map cleanly onto modern Anglo-American will doctrine. Second, in early English usage, testamentum was applied more broadly to conveyancing instruments generally — a usage that has no modern counterpart and that can mislead researchers reading medieval sources. A document described as a testamentum in a thirteenth-century English context may not be a will at all in the modern sense.
Why It Matters in Research
Researchers encounter testamentum most often in three contexts, each requiring different interpretive caution.
In Roman law sources and civilian treatises, testamentum is a technical term of art embedded in a distinct doctrinal structure. The rules governing testamentary capacity, form, revocation, and interpretation under Roman law differ substantially from common law doctrine. Researchers using civilian sources — including Bracton, which draws heavily on Roman models — should not assume that testamentum operates identically to the English "will."
In medieval English records, the broader usage identified by Spelman and reflected in Bracton means that testamentum may describe conveyancing instruments, not mortuary dispositions. Confusing these documents with testamentary instruments in the modern sense can produce serious research errors. Bracton's treatment of testamentum as a species of donatio mortis causa further complicates matters: it places the concept at the intersection of gift law and succession law, not cleanly within either.
In Magna Carta scholarship and early parliamentary sources, testamentum appears in provisions governing executors and the administration of decedents' estates (see Magna Carta, 9 Hen. III, c. 18, cited in Burrill). These references are relevant to the history of executor law and the ecclesiastical jurisdiction over wills, both of which are essential background for understanding English probate practice before the Judicature Acts.
Researchers should also be alert to the fact that Anderson's Dictionary of Law does not contain a substantive entry for testamentum, which reflects a general pattern: dictionaries organized around Anglo-American common law terms sometimes omit or underserve Latin civilian vocabulary. Gaps in secondary dictionary support are a signal to consult primary civilian sources and Bracton directly.
Historical Dictionary Support
Black's Law Dictionary (both the first and second editions) and Burrill's Law Dictionary agree on the core dual meaning: testamentum denotes a will or testament in both civil and early English law, and carries the additional broader English usage as a general conveyancing instrument. The two Black's editions are essentially identical on this point.
Burrill adds the most substantive historical detail, noting Bracton's treatment of testamentum as a species of donatio mortis causa and citing Bracton folio 60 and Fleta, book 2 — references that are genuine and usable. Burrill also flags the Magna Carta connection to executor practice, which neither Black's edition develops.
Spelman's derivation theory (testamentum from testes, witnesses) is reported by both Black's editions but should be understood as a historical etymology rather than settled philology. Modern scholarship on Latin legal terminology is more cautious about this derivation.
Anderson's Dictionary of Law provides no substantive entry for this term. The passage reproduced in the source material is from an unrelated entry and offers nothing on testamentum.
Jurisdictional Note
Testamentum as a living legal term is found primarily in civilian jurisdictions and in historical legal materials. In modern Anglo-American practice, the term appears only in its Anglicized descendant forms — testament, testamentary, last will and testament — and the Latin form is encountered principally in historical, comparative, and ecclesiastical law research.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Wills and Testaments — Historical Development; Donatio Mortis Causa; Roman Law and the Common Law Tradition.