Definition
A Latin phrase meaning "to itinerate" or "to travel on circuit." The phrase appears in medieval English legal texts as part of the formal designation for justices assigned to travel from county to county to hold court. The full form — justitiarii ad itinerandum de comitatu in comitatum — denotes justices appointed to travel systematically through the counties of England for the purpose of administering justice, hearing pleas, and performing royal judicial business in each locality. These traveling justices were the institutional mechanism by which the English crown extended centralized judicial authority into the regions before any permanent local court infrastructure existed.
Why It Matters in Research
Ad itinerandum is a term researchers will encounter almost exclusively in medieval and early common law sources. It does not appear in modern legal usage and has no living procedural or statutory context. Its primary research relevance is as a key to understanding the eyre system — the periodic judicial circuits that were a foundational institution of English common law from the twelfth through the fourteenth centuries.
Researchers working in early common law materials, English legal history, or the origins of circuit court systems will find ad itinerandum embedded in Bracton and similarly aged treatises, typically as part of the formal commissioning language for justices in eyre. Knowing the phrase is essential to parsing those passages accurately, since the Latin is dense and the institutional referent — the itinerant justice — is not intuitive to modern readers.
A key navigational point: ad itinerandum connects directly to the term iter (a journey or circuit) and to the institutional history of the eyre. Researchers who follow the cross-reference to iter in historical dictionaries will find the fuller picture of how these circuits were organized, what jurisdiction the traveling justices carried, and how the institution declined as the common law courts at Westminster became more accessible and as assizes replaced eyres for many purposes.
There is also a broader comparative thread worth noting. The English eyre system developed in rough parallel with similar circuit-riding institutions in other medieval European kingdoms, and researchers in comparative legal history may find ad itinerandum a useful entry point into that literature. For American legal historians, the phrase is background for understanding why circuit-riding by judges was considered natural and even necessary in early American practice — the institutional logic traveled with the common law.
Historical Dictionary Support
Burrill's Law Dictionary provides the essential entry: the phrase means "to itinerate," and is used in the compound designation justitiarii ad itinerandum de comitatu in comitatum, citing Bracton folio 108b. Burrill cross-references iter and justitiarius, which are the correct companion entries for a full understanding of the institution.
The Burrill entry is brief but accurate. It captures the phrase's meaning and its classical source without overreaching. What historical dictionaries generally do not supply — and Burrill is no exception — is the institutional context: the eyre as a specific administrative and judicial mechanism, the frequency and scope of the circuits, the breadth of jurisdiction the itinerant justices exercised (which was sweeping, often covering pleas of the crown, financial accounting, and local administrative inquiries simultaneously), and the reasons the institution eventually fell out of use. Researchers relying solely on dictionary entries for this term will have the correct translation but will need to supplement with legal history sources to understand what the institution actually did.
The citation to Bracton (De Legibus et Consuetudinibus Angliae, folio 108b) is the authoritative primary source for the phrase. Bracton's treatise, composed in the mid-thirteenth century, remains a principal reference for early English common law and is the natural next stop for any researcher who needs more than the dictionary gloss.
Jurisdictional Note
Ad itinerandum is a term of English medieval law with no direct American, Scottish, or civilian law equivalent. Jurisdictions that inherited the common law tradition inherited the circuit-court concept that descended from the eyre system, but the Latin phrase itself belongs to the English historical sources and does not appear in the legal vocabulary of any modern jurisdiction.