Definition
De son tort (Law French: "of his own wrong") is a phrase designating liability that arises when a person acts in a legal capacity without authority or right to do so. The phrase appears most commonly in two distinct legal contexts:
1. Executor de son tort: A person who, without valid appointment and without legal authority, intermeddles with the estate of a deceased person — taking possession of assets, paying debts, or otherwise acting as if they were a duly appointed executor. Because the person has assumed the role voluntarily and without right, the law treats them as a de facto executor for purposes of liability: they bear the obligations of a properly appointed executor but without the corresponding protections or powers. They may be sued by creditors and legatees, and they cannot benefit from the estate.
2. Trustee de son tort: By extension, the same principle applies in equity to persons who assume control over trust property without authority. A person who receives or deals with trust assets in a manner inconsistent with the trust, while knowing of the trust's existence, may be treated as a trustee de son tort and held to the duties and liabilities of a properly constituted trustee.
The phrase captures a broader doctrinal principle: voluntary assumption of a legal role creates the obligations of that role, even absent formal appointment.
Common Language
Modern common usage (Wiktionary): "Without authority or right (to do something)."
The Wiktionary definition captures the phrase's general sense accurately but strips away its functional legal consequence. In law, de son tort is not merely a description of wrongfulness — it is the legal mechanism by which liability attaches. The person who acts de son tort is not simply a wrongdoer; they are treated as if they had been properly appointed, and obligations run with that status. The common meaning suggests only that something was done improperly; the legal meaning goes further, imposing fiduciary-equivalent duties on the improper actor.
Recognized Forms
/SUBTYPES
Executor de son tort: The foundational form. A stranger to the estate who intermeddles with the decedent's property — collecting debts, paying creditors, disposing of assets — without letters testamentary or letters of administration. The common law subjected such a person to the full liability of a properly appointed personal representative.
Trustee de son tort: Equity's extension of the executor doctrine. A person who receives or administers trust property without authority, knowing of the trust, is held to trustee-level duties. This form is significant in modern trust litigation and constructive trust analysis.
Administrator de son tort: Less commonly, the same logic applies when the intermeddling occurs in an intestate estate where no executor could have been appointed. The intermeddler is treated as a de facto administrator.
Why It Matters in Research
The phrase is almost always encountered in abbreviated or embedded form — most frequently in the compound "executor de son tort" — and researchers scanning older case digests or estate litigation records may miss it if searching only for the full phrase. Historical sources use "de son tort" as a standalone phrase (as all four source dictionaries do), while modern sources tend to integrate it directly into the compound term.
The executor de son tort doctrine appears in probate law, creditor's rights litigation, and estate administration disputes. In equity sources, the trustee de son tort variant appears in constructive trust analysis and breach of fiduciary duty claims. These bodies of law are indexed separately in most digests, so a complete research picture requires searching both probate and equity materials.
Chronologically, the doctrine's intensity has shifted. Pre-20th century sources focus almost entirely on the executor form, treating it as a probate mechanism. 20th century sources, particularly in trust law, develop the trustee variant more extensively. Researchers working in post-1950 materials will find the trustee de son tort analysis considerably more developed than the historical dictionary entries suggest.
One research trap: Rapalje & Lawrence's entry redirects without substantive explanation, cross-referencing EXECUTOR without elaborating on de son tort itself. Researchers relying on Rapalje alone will underestimate the doctrine's scope.
A secondary trap: the phrase is sometimes used loosely in older opinions to describe any wrongful intermeddling without formal legal authority, not just estate or trust contexts. Context is essential to determine which form of the doctrine is in play.
Historical Dictionary Support
The historical sources present a narrow, uniform definition centered on the executor form. Black's (both editions) and Burrill agree verbatim: "a stranger who takes upon him to act as an executor without any just authority." All three cite the same foundational authority — Blackstone's Commentaries (2 Bl. Comm. 507) and Stephen's Commentaries (2 Steph. Comm. 244) — reflecting the doctrine's stable common law pedigree through the 19th century.
Rapalje & Lawrence's entry is an outlier, redirecting to EXECUTOR without defining the phrase and instead trailing off into a description of the unrelated writ de recto de dote. This appears to be a typographical or organizational error in the original dictionary — the entry conflates two separate headings — and should not be relied upon for substantive content.
What the historical sources collectively miss: the equity extension to trustees. All four dictionaries treat de son tort solely as a probate doctrine. The trustee de son tort doctrine, though developed in chancery courts well before these dictionaries were published, receives no treatment here. Researchers should treat the historical entries as incomplete on this point and supplement with equity treatises.
Jurisdictional Note
The executor de son tort doctrine is recognized across common law jurisdictions, though modern probate codes in many U.S. states have partially codified or modified liability rules for unauthorized intermeddlers. English law retains the doctrine more explicitly. The trustee de son tort variant is applied more consistently in equity-based jurisdictions and in states with developed trust codes; its availability and scope may vary where trust statutes have displaced common law fiduciary principles.