Definition
De libera piscaria (Latin: "of free fishery") is an old common law writ used to enforce a claimed right of free fishery — that is, an exclusive or privileged right to fish in a particular body of water. The writ belonged to the family of writs known as quod permittat, which were used to compel a defendant to permit the plaintiff to exercise a right the defendant was obstructing. Where a person entitled to a free fishery was being prevented from exercising that right, de libera piscaria provided the procedural mechanism to vindicate the claim.
The underlying substantive right — free fishery — was a profit à prendre or incorporeal hereditament, meaning a right appurtenant to land or granted by royal grant, entitling the holder to take fish from waters belonging to another or from a defined stretch of water to the exclusion of others.
Common Confusion
Free fishery, common of fishery, and several fishery are three distinct fishing rights in historical English law, and sources do not always use the terms consistently. A free fishery was typically an exclusive right in another's water, most often derived from royal grant. A several fishery was an exclusive right in one's own water, or in water over which the owner had sole dominion. A common of fishery was a non-exclusive right shared with others, including the public in some navigable waters. Researchers encountering any of these terms in historical deeds, pleadings, or abridgments should not assume interchangeability — the nature of the right and who held it determined which writ or remedy applied.
Why It Matters in Research
This term appears almost exclusively in early English common law materials — Year Books, the Register of Writs (Registrum Brevium), and abridgments of pleading. By the time American legal materials become prominent, de libera piscaria as an active writ had largely faded from practice, making it a term researchers will encounter when tracing the procedural history of property rights in fisheries rather than in modern litigation.
The key navigational point: de libera piscaria is the writ; free fishery is the right. When researching one, the other must be examined. The quod permittat family of writs — of which this is a species — operated as a form of nuisance or obstruction remedy, and understanding that procedural category is necessary to interpret how this writ functioned within the common law system.
Researchers working in early land records, colonial grants, or riparian rights disputes may encounter the underlying free fishery right without the writ ever being named. Conversely, researchers in historical pleading materials may encounter the writ form without the substantive property context being explained. The two bodies of material need to be read together.
Because fishing rights in American law developed along different lines — shaped by public trust doctrine, state ownership of navigable waters, and riparian rights principles — the English writ itself has no American procedural descendant. Its value is historical and comparative.
Historical Dictionary Support
Both Black's Law Dictionary editions define de libera piscaria identically and tersely: "a species of quod permittat," with a citation to the Register of Writs (Reg. Orig.) at folio 155. This is accurate as far as it goes, but both entries are notably minimal — they identify the procedural category without explaining the underlying property right, the historical context of royal fishery grants, or the distinction from related fishing rights. Researchers relying solely on Black's would know the writ's procedural genus but not its substantive content or practical use.
The citation to the Registrum Omnium Brevium (the Register of Original Writs) is the authoritative anchor for the writ's form and is consistent across editions. The historical dictionaries converge entirely on this framing; there is no divergence between them, which reflects their shared brevity rather than any genuine agreement on a contested point.
Jurisdictional Note
De libera piscaria is a writ of English common law origin and has no direct equivalent in American civil procedure. Fishing rights in the United States are governed by a combination of state public trust doctrine, riparian rights law, and statutory frameworks that displaced the English incorporeal hereditament structure. American courts have occasionally cited the historical English distinction between free fishery, several fishery, and common of fishery when construing colonial-era grants or early land patents, but the writ itself is not operative in any American jurisdiction.