Definition
A writ issuing out of chancery that delegated specific judicial or quasi-judicial authority to named private persons or commissioners, empowering them to perform acts that would otherwise require the presence of the court or a designated officer. The Latin phrase translates literally as "we have given power," and the writ functioned as the formal vehicle by which that grant of delegated authority was conveyed.
In English practice, the writ was used principally for two purposes: (1) authorizing commissioners to administer oaths to defendants in chancery proceedings and to take their answers out of court — a practical mechanism when defendants resided at a distance from the court; and (2) authorizing the administration of oaths of office to newly appointed justices of the peace. In earlier periods, the writ extended to a much broader range of functions, including the appointment of attorneys and the acknowledgment of fines and other conveyances.
The writ was a creature of English chancery practice and, as a formal instrument, has no living counterpart in modern American procedure. Its functions have been absorbed into statutory commissions, letters rogatory, depositions by commission, and the administrative machinery for swearing in public officers.
Common Confusion
DEDIMUS POTESTATEM is sometimes loosely equated with a general commission or letter rogatory. The distinction matters: the dedimus potestatem was a formal writ of the court of chancery, not a mere letter of request to a foreign court or a private arrangement. Its authority derived from the writ itself, not from the consent of the receiving jurisdiction. Researchers encountering references to commissions to take testimony in early equity proceedings should verify whether the source instrument was a dedimus potestatem or a later statutory commission — the procedural rules and evidentiary weight attached differed accordingly.
Why It Matters in Research
This term appears almost exclusively in historical English and early American legal materials. Researchers will encounter it most often in:
— Chancery records and equity pleadings from the seventeenth through nineteenth centuries, where it identifies the procedural mechanism by which a defendant's answer was taken outside London.
— Early American colonial and post-colonial practice. American equity courts, particularly in the South and Mid-Atlantic, borrowed chancery forms directly from English practice, and dedimus potestatem commissions appear in case files and court orders well into the early nineteenth century. By the mid-nineteenth century, statutory provisions for taking depositions by commission had largely displaced the writ, but older published records and digests will still use the term.
— Justice of the peace materials. The writ's role in administering the oath of office to newly commissioned justices of the peace generated a distinct body of practice. Stone's Justice of the Peace (cited in Rapalje & Lawrence) addresses this function specifically. Researchers working on the history of local magistracy or the formal qualification of officers should be alert to this usage.
The primary navigational trap is temporal: the scope of the writ contracted significantly over time. Materials from the sixteenth and seventeenth centuries will describe uses — appointment of attorneys, acknowledgment of fines — that had become obsolete by the time Blackstone wrote. Citing an early source for the writ's scope without noting this contraction will produce an anachronistic account of what the writ did in a later period.
A secondary trap is jurisdictional transplantation. American courts adopting equity procedure did not uniformly carry over the full English dedimus potestatem practice. Some states replaced it entirely by statute at an early date; others preserved chancery forms longer. The presence of the term in an American source does not confirm that English chancery rules governed its operation.
Historical Dictionary Support
The four source dictionaries are in close agreement on core definition and function, all drawing on Blackstone's Commentaries (3 Bl. Comm. 447) as the primary authority. Burrill adds a reference to Cowell's Interpreter, which provides the older formulation: "a writ whereby a commission is given to a private man" — language that usefully highlights the delegation-to-private-persons character of the instrument, distinguishing it from a commission running to a judicial officer.
Rapalje & Lawrence narrows the definition to the justice-of-the-peace oath function, citing Stone's Justice of the Peace, which reflects the writ's surviving practical relevance at the time of writing rather than its full historical scope. This is a meaningful compression that researchers relying on Rapalje alone would need to supplement.
None of the historical dictionaries address American statutory displacement of the writ or give guidance on tracing its procedural evolution in American equity practice — a gap that requires consultation of state chancery rules and statutory compilations rather than any of these general dictionaries.
Jurisdictional Note
The dedimus potestatem was a writ of the English court of chancery and as such had no native American counterpart. American equity practice absorbed its functions through a combination of direct chancery form-borrowing and early statutory provision. Researchers should not assume uniform American treatment — the applicable rules will be found in state equity rules, chancery court orders, and legislative acts rather than in any general reception of English chancery practice.