Definition
En son damage is a Law French phrase meaning "in his damage" or "doing him damage." It appears in medieval English law to describe the situation of a person or animal found on another's land in a manner that causes harm to the owner or occupant — most directly as a descriptor accompanying the concept of damage feasant. The phrase identifies the wrongful or injurious character of the presence: the trespassing person or beast is there not merely without right, but actively to the detriment of the land's possessor.
The phrase functions as a legal qualifier rather than a standalone cause of action. It answers the question of how or in what capacity a trespass was occurring: not just on the land, but in the owner's damage — destroying crops, consuming grass, or otherwise injuring the property.
Common Language
The phrase has no meaningful presence in modern common English. En son damage is pure Law French legal vocabulary with no current ordinary usage. Omitted accordingly.
Common Confusion
En son damage is closely linked to — and easily collapsed into — damage feasant (or dommage feasant), the doctrine permitting an aggrieved landowner to distrain animals found trespassing and causing damage on the property. The two phrases are not synonymous. Damage feasant names the doctrine or the legal condition of the animal. En son damage is the descriptive phrase characterizing the trespass — it explains that the animal or person is present in a way that causes harm. In practice, historical sources often use the phrases in immediate proximity, which can obscure the distinction between the doctrine and its factual predicate.
Why It Matters in Research
Researchers working in early English legal sources — Year Books, Britton, Bracton, or their derivatives — will encounter en son damage embedded in passages about distress and trespass rather than appearing as a headword. Because it functions as a modifying phrase rather than a cause of action, it will rarely appear indexed independently in finding aids or tables of contents. Researchers should treat it as a marker: its presence in a source signals discussion of damage feasant, the right of distress, or the liability of a trespassing party for harm done.
The phrase illustrates the dual French-Latin character of medieval English legal vocabulary: Burrill records the Law Latin equivalent as in damno suo, and researchers may encounter both forms in the same manuscript or treatise depending on the author's habits. Translating one form but not recognizing the other can cause researchers to miss parallel passages.
Because en son damage describes the factual quality of the trespass rather than a remedy, it also appears in records concerning pleading — specifically, in the framing of a trespass count to establish that the intrusion was not merely technical but materially injurious. This has implications for how a researcher reads early plea rolls: the phrase is doing work in the pleading structure, not simply decorating a narrative account.
There is no modern legal doctrine that preserves this phrase in active use. Researchers encountering it should calibrate their sources to the medieval and early modern common law period.
Historical Dictionary Support
Burrill's Law Dictionary is the primary historical source for this entry and provides the essential gloss: "in his damage; doing him damage." Burrill directly cross-references damage feasant and supplies the illustrative quotation from Britton: "En son pree, ou en ses blees, ou aillours en son damage" — "in his meadow, or in his corn, or elsewhere in his damage." This passage from Britton (chapter 27) is the most concrete surviving example of the phrase in context, showing that it applied to animals found damaging specific types of agricultural property.
Burrill also provides the Latin equivalent in damno suo, which confirms the phrase's function as a descriptive qualifier. No other major historical legal dictionaries in the Law Mind corpus provide independent treatment of this phrase, which reflects its status as a supporting element of damage feasant doctrine rather than a term carrying independent doctrinal weight. The historical record is consistent but thin: the phrase was understood well enough by practitioners of the period that extensive definition was not attempted.
Jurisdictional Note
En son damage is a term of historical English common law. It has no separate doctrinal development in American, Scottish, or other common law jurisdictions. Researchers working in colonial American records may encounter it in materials derived from English practice, but it carries no independent American legal history.