Definition
A blasarius is a Latin term from medieval and early modern legal usage denoting an incendiary — a person who maliciously sets fire to property or buildings. The term appears in historical legal texts and glossaries as a label for the offender rather than the offense itself.
---
Common Confusion
BLASARIUS vs. INCENDIARY: These terms are functionally equivalent in historical legal sources, with blasarius simply being the Latinized form used in formal or ecclesiastical legal proceedings. Modern researchers should not read meaningful distinction between the two. "Incendiary" survives into modern law (and ordinary English) while blasarius has no contemporary legal usage.
---
Why It Matters in Research
Blasarius is a term of historical record only. It appears in Latin legal glossaries, medieval plea rolls, and early common law treatises where Latin nomenclature was standard. Researchers encountering this term will find it almost exclusively in pre-17th-century sources or in later glossaries that catalog such terms.
Two practical points for corpus navigation. First, the term is entry-level in historical dictionaries — all three sources in the Law Mind shelf define it with a single word ("incendiary") and offer nothing further. Rapalje & Lawrence attribute the term to Blount, meaning Thomas Blount's Nomo-Lexicon (1670), which is the likely proximate source for subsequent dictionary entries. Researchers tracing the term's usage should begin there rather than treating Black's entries as independent authority. Second, when searching historical records for arson-related prosecutions, blasarius is the Latinate form you may encounter in formal pleadings or clerical records, while the underlying common law offense would have been charged under arson doctrine. The two concepts track together but the terminology shifts depending on whether the source is in Latin or English.
The term has no doctrinal weight. It does not carry elements, defenses, or a distinct common law test. Its value is terminological and interpretive — identifying what class of offender is being described in a Latin-language source.
---
Historical Dictionary Support
All three historical sources — Black's Law Dictionary (both editions) and Rapalje & Lawrence — define blasarius identically as "an incendiary." This unanimity reflects not independent research but the characteristic practice of 19th-century legal lexicographers copying from earlier glossaries, with Blount's Nomo-Lexicon as the apparent common ancestor. The brevity of all three entries is itself informative: these dictionaries treated blasarius as a vocabulary item worth cataloging for Latin-fluent practitioners, not as a term carrying any active doctrinal significance. None of the sources discuss the historical offenses for which a blasarius might be prosecuted, the penalties applicable, or the procedural context in which the term appeared. Researchers should not mistake the dictionary entry for a complete account of how arson or incendiarism was treated in the periods when this term was in active use.
---
Jurisdictional Note
Blasarius is a term of historical Latin legal vocabulary without jurisdiction-specific variation. Its practical appearance is limited to English and continental European legal sources predating the widespread shift from Latin to vernacular in legal proceedings.
---