Definition
Constitutiones (singular: constitutio) were imperial enactments in Roman law — legislative pronouncements issued by the Roman Emperor carrying the force of binding law. The term encompasses the full range of instruments through which the Emperor exercised his lawmaking authority, from broad edicts of general application to narrow rulings directed at specific individuals or cases.
Three principal forms are recognized:
1. Edicta — General proclamations issued by the Emperor on his own initiative, addressed to all persons within the empire or within a particular province. These functioned closest to what modern lawyers would recognize as statutes.
2. Decreta — Judicial decisions rendered by the Emperor in his capacity as supreme judge, resolving disputes brought before him. Decreta of sufficient importance could acquire general precedential force beyond the parties.
3. Rescripta (also called epistolae) — Written responses by the Emperor to petitions or inquiries submitted by judges, magistrates, officials, or private persons seeking guidance on a point of law. Rescripta were technically addressed to the inquirer but were frequently treated as authoritative statements of law applicable to similar circumstances.
Some constitutiones were general (generales) — intended to establish a rule for all future cases of the same kind. Others were personal (personales) — directed to a specific individual or situation and not meant to govern beyond that instance. The distinction was legally significant: personales did not bind courts in later cases.
The Emperor's power to issue constitutiones derived from the grant by the Senate and people of Rome of authority equivalent to that of the highest republican magistrates, combined with the accumulated practice of the Principate. Imperial constitutiones were eventually compiled and systematized in the Codex Theodosianus (438 CE) and, most influentially, in the Codex Justinianus, the first part of the Corpus Juris Civilis (529–534 CE).
---
Common Confusion
Do not conflate constitutiones with modern constitutional law. A Roman constitutio is not a constitution in the modern sense — it is not a foundational charter limiting governmental power. The word shares a Latin root but describes something closer to a royal decree or executive order. Researchers encountering the term in civil law treatises, canon law texts, or early common law sources referencing Roman authority should not read modern constitutional significance into it.
---
Recognized Forms
/SUBTYPES
The three principal subtypes — edicta, decreta, and rescripta — are formally recognized in Roman legal scholarship and carried distinct procedural contexts and degrees of general applicability. A fourth category, mandata (administrative instructions to provincial governors), is sometimes listed but treated as less significant in classical doctrine.
---
Why It Matters in Research
This term appears primarily in two research contexts: (1) Roman law scholarship and civil law history, and (2) English legal history, where civilian-trained writers and ecclesiastical courts drew on Roman imperial law concepts.
Researchers working in the civilian tradition must track the term across its three subtypes, which are not interchangeable. A rescript answering a private petition is a very different authority than a general edict. Many primary sources — including Justinian's Institutes and the Digest — use constitutio generically without specifying the subtype; context and date often determine which form is meant.
In the canon law tradition, the term migrated into papal usage: papal constitutiones (papal constitutions) borrowed the Roman imperial form to describe solemn legislative enactments of the Pope. Researchers encountering constitutio in medieval ecclesiastical sources should determine whether the reference is to Roman imperial law or to a papal constitution — these are distinct instruments requiring different secondary literature.
For common law researchers, the term is largely encountered in treatises that engaged seriously with Roman law sources, such as those in the civilian tradition influencing English admiralty and ecclesiastical courts. It rarely appears in purely common law holdings but is significant context for understanding what learned counsel were arguing.
The historical dictionaries in the Law Mind corpus are in agreement on the basic definition but their entries are truncated — the passages break off at "the emperor had this power of irre[vocable]..." — leaving the statement of imperial authority incomplete. Researchers should not rely solely on these entries for a complete doctrinal account of the emperor's lawmaking power.
---
Historical Dictionary Support
All three source dictionaries — both editions of Black's and Rapalje & Lawrence — provide substantially identical definitions, reflecting a shared understanding settled firmly by the late nineteenth century. Each identifies the same three subtypes (edicta, decreta, rescripta/epistolae) and the same general/personal distinction. No meaningful divergence exists among them on substance.
The entries are notable for what they omit: none discusses mandata as a subtype, none addresses the Corpus Juris Civilis as the vehicle through which constitutiones reached Western legal education, and none distinguishes clearly between classical Roman practice and Justinianic compilation. For research purposes, these dictionary entries provide reliable identification of the term but limited analytical depth. Civilian treatises — particularly those in the natural law and institutional traditions — are required for fuller treatment.
---
Jurisdictional Note
Constitutiones as Roman imperial enactments have no direct application in U.S. or English common law. Their relevance is historical and comparative. In civil law jurisdictions with strong Roman law foundations — Louisiana, Quebec, Scotland, and most of continental Europe — understanding constitutiones is essential background for tracing the intellectual genealogy of modern legislative and regulatory authority.
---
Encyclopedia Cross-Reference
The Law Mind Constitutional Law Encyclopedia entry on Constitutional Interpretation — Originalism, Textualism, and Living Constitutionalism is a distant relative conceptually but not a direct match; that entry addresses modern U.S. constitutional theory. Researchers interested in the development of Roman legal texts as sources of interpretive authority may find useful comparative context there, but the primary research path for constitutiones leads to Roman law and civil law encyclopedia sources.
---