Definition
Purprestura (also rendered *purpresture*) is a term from old English law denoting an encroachment upon or wrongful seizure of land or rights belonging to the Crown or a lord — typically by enclosing, building upon, or otherwise appropriating land held in common or belonging to the sovereign without license or authority. The offense consisted in the unauthorized occupation of royal forests, highways, navigable waters, or other public or common ground, thereby narrowing or usurping what was held for general use or for the Crown.
In its classic application, purprestura described acts such as erecting structures on the king's highway, enclosing parcels of royal forest, or building upon the foreshore or other ground in which the Crown held a possessory interest. It was not mere trespass — it carried the sense of a permanent or continuing encroachment that diminished the Crown's domain or the public's right of way.
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Common Confusion
Purprestura is sometimes conflated with *waste* (vastum) and *assart* (essartum), the three terms frequently appearing together in medieval forest law instruments. They are distinct: waste is the act of damaging or spoiling land or timber; assart is the grubbing up of forest land to convert it to arable; purprestura is the encroachment itself — the seizing of land or space by building or enclosing. The Latin passage preserved in Burrill — addressing those who commit *vastum vel purpresturam* or *essartum* in the royal forests without license — illustrates exactly this tripartite distinction. Researchers encountering any one term in a medieval or early modern forest record should expect to find the others nearby.
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Why It Matters in Research
Purprestura is primarily a term of medieval and early modern English law and will appear most frequently in records touching royal forests, Crown land administration, eyre proceedings, and inquiries into encroachments on common rights or the king's highway. Several research traps are worth flagging:
**Spelling variation is significant.** Historical records use *purprestura* (Latin form), *purpresture* (anglicized), *purpresture*, and occasional variant spellings. Any corpus search should account for all forms; searching only the Latinate spelling will miss anglicized usages in Year Books and later treatises.
**The tripartite cluster.** As noted above, purprestura almost always appears alongside vastum (waste) and essartum (assart) in forest law contexts. A researcher tracing purprestura through a corpus should treat these three terms as a conceptual unit and follow all three threads.
**Eyre records and forest pleas.** The primary documentary home for purprestura is the records of the forest eyres and general eyres, where commissioners inquired into encroachments on royal demesne. Researchers working with plea rolls, forest rolls, or inquisitions from the twelfth through fourteenth centuries will encounter this term in formal presentments.
**Transition to nuisance doctrine.** By the later common law period, many of the fact patterns covered by purprestura — encroachments on highways, obstruction of navigable waters — migrated into the law of public nuisance. The older term effectively dissolved into nuisance doctrine over time, which means a researcher tracing the legal treatment of, say, building on a public road must pivot from purprestura in medieval sources to public nuisance in post-medieval ones.
**No modern statutory life.** Purprestura has no active role in contemporary statutory or case law. It appears in modern legal writing almost exclusively in historical or academic contexts. Researchers should not expect to find it operative in materials after the seventeenth century without explanation.
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Historical Dictionary Support
Burrill's Law Dictionary identifies purprestura as a Latin form used in old English law and cross-references *purpresture* as the anglicized equivalent. The illustrative passage Burrill preserves — drawn from a royal instrument addressing encroachments in the royal forests — captures the term in its natural habitat: a directive against those who commit *vastum vel purpresturam sine licentia* (waste or purpresture without license) or *essartum* (assarting). This passage is genuinely instructive because it shows the term operating as one member of a fixed legal triad and confirms that the defining feature of purprestura was the absence of royal license — what would otherwise be encroachment could be authorized by grant.
Burrill does not develop the doctrinal contours of the term at length, and historical legal dictionaries generally give it thin treatment relative to its importance in medieval land law. Researchers needing fuller doctrinal context should look to treatises on English forest law and the records literature surrounding the forest eyres, which provide richer material than the dictionary tradition alone.
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Jurisdictional Note
Purprestura is a term of English law with no direct counterpart in continental or American legal traditions. American property and nuisance law developed from the common law inheritance but did not carry the term forward; researchers working in American legal sources will not encounter it except in historical discussion.
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