Definition
To make a building serve as a castle; the act of converting or fortifying a structure so that it functions in the manner of a castle. A term from medieval Latin used in legal and feudal contexts to describe the adaptation of an otherwise ordinary building — a manor house, tower, or fortified residence — into a defensive stronghold carrying the legal and social status of a castle.
Why It Matters in Research
Incastellare is a term of medieval feudal law with no surviving operational role in modern legal practice. Researchers are most likely to encounter it in one of three contexts: (1) glossaries and abridgments tracing early English property and tenure concepts; (2) historical scholarship on the Norman and Angevin periods, when the right to crenellate — to fortify a structure — was a royal prerogative requiring a license; and (3) Latin maxim collections and law dictionaries, where it appears clustered alongside incaustum, incendium, and similar Latin terms with no direct doctrinal relationship.
The term's proximity in historical dictionaries to incaustum (ink) and to maxims about fire and debt is a function of alphabetical arrangement, not legal relationship. Researchers skimming these entries should not read conceptual connections into the cluster.
The licensing dimension is worth noting for historical property research. In medieval English law, unauthorized fortification of a building — incastellare without royal license — was a serious trespass against the Crown. The license to crenellate was a distinct royal grant, and the distinction between a lawfully fortified residence and an unlawfully converted castle had real consequences for tenure, forfeiture, and Crown authority. Neither Black's, Bouvier's, nor Rapalje & Lawrence develops this dimension; researchers working on medieval fortification, crown prerogative, or feudal tenure will need to look beyond these dictionary sources.
For corpus researchers, the term is useful primarily as a navigational waypoint. Its appearance in a historical document signals engagement with feudal property concepts and may indicate proximity to discussion of tenure, castleguard, the assize of arms, or related medieval English land law.
Historical Dictionary Support
All four sources agree precisely: incastellare means to make a building serve as a castle. The definition traces in every case to Jacob's Law Dictionary, an 18th-century English law glossary, suggesting the term entered the common law dictionary tradition through a single lineage rather than through independent legal usage.
No source elaborates on the feudal context, the licensing requirement, or the procedural significance of unauthorized fortification. The entries function as translation glosses — Latin to English — rather than as doctrinal explanations. Bouvier's adds nothing beyond Jacob. Black's first and second editions are identical. Rapalje & Lawrence follows the same pattern.
The brevity and uniformity of these entries reflects the term's status: it was already archaic by the time these dictionaries were compiled, preserved for completeness rather than practical utility.