Definition
The Mad Parliament refers to the assembly convened at Oxford in 1258, historically distinguished by the radical nature of its measures and the forceful manner in which it confronted royal authority. It is known in Latin as the Parliamentum Insanum. The gathering produced the Provisions of Oxford, a landmark set of reforms that imposed institutional constraints on the English crown by establishing a council with supervisory power over the king's government. The term itself is not a legal concept with operative modern effect but is a proper historical designation for a specific constitutional event in the development of English parliamentary governance.
Common Confusion
Bouvier's entry dates the Mad Parliament to 1368, but this is an error. The assembly universally identified by historians and constitutional scholars as the Mad Parliament — the one producing the Provisions of Oxford — convened in 1258 under Henry III. No parliament of comparable constitutional significance or notoriety meets under that name in 1368. Researchers relying on Bouvier's date without cross-checking will be misled. The Latin designation Parliamentum Insanum confirms the 1258 assembly as the correct referent.
Why It Matters in Research
This term appears almost exclusively in historical and constitutional history contexts. Its research value lies entirely in what it represents: an early episode in the long struggle between crown and magnates that produced, by degrees, the constitutional architecture of parliamentary supremacy. Researchers tracing the development of English parliamentary institutions, the concept of counsel and consent, or the origins of conciliar government will encounter this term as a waypoint.
The Provisions of Oxford, which the Mad Parliament produced, required the crown to govern through a council of fifteen, mandated regular parliaments, and imposed accountability on royal ministers. These provisions were later reinforced and complicated by the Provisions of Westminster (1259) and became a flashpoint for the Second Barons' War. Researchers working in the constitutional history of the thirteenth century should treat the Mad Parliament as one node in a connected sequence running from Magna Carta (1215) through the Barons' Wars to the Model Parliament of 1295.
The "madness" of the name warrants attention. It was applied by supporters of royal prerogative to discredit the assembly's radicalism, not by the reformers themselves. Understanding the polemical origin of the label matters when assessing how later writers — including those whose works appear in historical legal dictionaries — characterize the event and its participants.
Corpus researchers should be alert to variant spellings and forms across Latin and English sources: Parliamentum Insanum, the Oxford Parliament, and the Mad Parliament are all in circulation. Index searches limited to one form will miss material indexed under the others.
Historical Dictionary Support
Bouvier's is the principal historical legal dictionary source for this term, and its entry is brief to the point of being skeletal: a one-sentence identification of the assembly, its date (given erroneously as 1368), its characterization as extreme and violent, and the Latin equivalent. The attribution to "Byrne" suggests Bouvier's compiler drew from a secondary source rather than primary materials.
The entry's brevity reflects the term's status in legal dictionaries: it is historical vocabulary, not doctrine. Bouvier's does not explain the Provisions of Oxford, the baronial coalition behind the parliament, or the constitutional consequences of the assembly. Researchers who stop at Bouvier's will have a label but no usable historical understanding. Constitutional history treatises and chronicle sources are the necessary supplements.
Jurisdictional Note
This term has no modern jurisdictional application. It belongs to the constitutional history of England and is relevant only to research concerning the development of English parliamentary institutions in the thirteenth century.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Provisions of Oxford; English Constitutional History; Development of Parliament