Definition
A Latin place-name used in historical legal documents to identify the location now known as Llantwit Major (or St. Llantwit), a town in Glamorganshire, Wales. The phrase translates literally as "the shrine" or "sanctuary of Saint Illtud," referring to the early Christian monastic site associated with Saint Illtud (Iltutus), a prominent Welsh ecclesiastical figure of the fifth and sixth centuries. In legal instruments — charters, grants, pleadings, and records — the Latin form was employed as the formal designation of the place, functioning as the operative geographic identifier in the same way modern addresses or parish names function today.
Why It Matters in Research
This term is a navigational artifact of medieval and early modern legal drafting practice, when place-names in Wales and other Celtic regions were routinely Latinized for use in formal instruments. Researchers encountering this phrase in a charter, patent roll, or ecclesiastical record should understand that it refers to the Llantwit Major area of Glamorganshire and not to any continental or Roman location, despite the conventional Latin structure of the phrase.
Several practical traps exist for the unwary:
First, Welsh ecclesiastical place-names were Latinized inconsistently across different periods and scriptoria. Variant spellings of the saint's name — Iltutus, Illtyd, Iltud, Iltuti — appear across different records, and the place itself is rendered variously in sources as Llanilltud Fawr, Llantwit Major, and St. Donat's-adjacent designations. A search confined to a single spelling will miss relevant documents.
Second, this term sits within a broader family of Fanum-prefixed Latin place-names used for Welsh and English locations associated with saints' shrines or monastic foundations. Burrill's entry pairs it immediately with FANUM IVONIS PERSA (St. Ives in Huntingtonshire), illustrating that these were working reference terms for practitioners who needed to decode place-names in historical instruments. The corpus researcher should treat all Fanum constructions as belonging to this same genre of saint-shrine toponyns requiring geographic resolution.
Third, Glamorganshire ecclesiastical and manorial records touching Llantwit Major may be indexed under any of its name variants in different archival collections. The Latin form is most likely to appear in pre-Tudor instruments, crown grants, and papal or episcopal documents; the Welsh and anglicized English forms dominate later administrative records.
Historical Dictionary Support
Burrill's Law Dictionary provides the only relevant entry in the Law Mind shelf sources, and it is characteristically terse: "St. Lantwit in Glamorganshire." This is sufficient for its purpose — a quick decoding reference for practitioners — but it offers no guidance on variant spellings, the saint's identity, or the class of instrument in which the term appears. Burrill groups the entry alongside FANUM IVONIS PERSA without editorial commentary, treating both as straightforward geographic decoding problems.
No other standard historical legal dictionaries in the Law Mind corpus address this term. Its absence from sources such as Jacob's Law Dictionary or Tomlin's Law Dictionary is unsurprising; such hyper-specific Latin place-name glosses were the specialty of practitioners' reference compilations rather than doctrinal legal dictionaries.
The historical record of Llantwit Major itself is substantial: the site was one of the most significant early Christian monastic centers in Wales, and its lands generated a long documentary history running through Norman, Plantagenet, and Tudor-era instruments. Researchers working in Welsh ecclesiastical history, land tenure, or monorial records will encounter this Latin form in that documentary context.
Jurisdictional Note
This term is geographically specific to Wales, and legal instruments using it will fall under the historical legal frameworks governing Welsh land tenure, ecclesiastical administration, and crown grants affecting Wales. Post-Acts of Union (1536–1543), Welsh administrative records increasingly shifted to English-language forms, making the Latin designation primarily a pre-Tudor or early Tudor phenomenon.