Definition
A Latin writ of medieval English procedure, translating literally as "let him follow at his own peril" or "let him come or take the consequences." The writ issued in the context of warranty proceedings when a defendant had been summoned three successive times — by original summons, alias, and pluries — to appear and defend a warranty claim (summons ad warrantizandum), and each time the sheriff had returned that nothing sufficient existed to compel appearance. Upon the failure of the pluries summons, sequatur sub suo periculo issued as a final compulsory process, placing the burden of appearance squarely on the summoned party under threat of adverse consequence. The writ was part of the obsolete machinery of real property warranty actions and has no operative existence in modern law.
Common Confusion
The phrase is occasionally rendered as a single word or run together in historical manuscripts and printed abridgments, creating transcription difficulties in older sources. Researchers should not confuse this writ with the broader doctrine of warranty in real property, which survived the abolition of the specific writ forms. The writ is also distinct from the summons ad warrantizandum itself: that earlier process initiated the warranty summons sequence, while sequatur sub suo periculo was the terminal process issued only after that sequence had been exhausted without result.
Why It Matters in Research
This term will almost never appear in modern legal research contexts and is of interest almost exclusively to historians of medieval and early modern English real property law and common law writ procedure. Several research points deserve attention:
The writ belongs to the highly formalized writ system that governed land actions before the common law reforms of the nineteenth century. Understanding it requires familiarity with the warranty structure of real actions — a body of law largely dismantled in England by the Real Property Limitation Act 1833 and subsequent reforms, and never fully transplanted into American common law. Researchers working in colonial American records or early state court records may encounter the term, but it was already archaic in most American practice by the founding period.
The citation in Bouvier to "O.N.B. 163" refers to the Old Natura Brevium, one of the foundational English treatises on writ forms. Researchers consulting Bouvier on this term should follow through to the Natura Brevium literature directly, as Bouvier's treatment is necessarily compressed.
In corpus searches, the Latin phrase may appear in variant spellings and word-boundary treatments depending on the period and typeface of the source. Historical legal manuscripts frequently contracted or elided Latin phrases; digital search of pre-1800 legal records should account for this.
The writ also illuminates the layered escalation logic of the common law writ system: original process, alias (second), pluries (third), and then a final compulsory writ. Researchers tracing procedural escalation patterns in real actions will find sequatur sub suo periculo as the terminus of this chain in warranty proceedings.
Historical Dictionary Support
Bouvier's Law Dictionary is the sole source in the Law Mind shelf that addresses this term, and its treatment is brief. Bouvier provides two complementary glosses: the procedural context (failure of alias and pluries summons in warranty proceedings) and the attributive note citing Byrne's Dictionary. Bouvier's translation — "let him come or take the consequences" — is a functional paraphrase rather than a literal rendering; it captures the coercive purpose of the writ accurately even if it departs from the strict Latin.
No entry for this writ appears in Black's Law Dictionary in its early editions as a standalone term, and it is not addressed in American treatises of the nineteenth century as a live writ, reflecting its obsolescence. The term's absence from later dictionaries is itself informative: it marks a writ that fell out of practice entirely rather than being absorbed into reformed procedure.
The Old Natura Brevium, to which Bouvier directs researchers at folio 163, is the primary primary source for the writ's operation. Fitzherbert's Natura Brevium and Rastell's Termes de la Ley are additional historical sources that would contextualize the broader writ family to which this term belongs, though they may not address sequatur sub suo periculo by name.
Jurisdictional Note
This writ was a creature of English common law procedure and had no meaningful American reception as an operative writ. Any appearance in American legal sources will be historical or academic. English practice abolished the relevant writ forms through nineteenth-century procedural reform legislation.