Definition
A Latin term from civil and early English law meaning "principal." Used in legal writing and maxims to designate three distinct roles:
1. Principal debtor: The primary obligor in a debt relationship, as distinguished from a surety or guarantor who stands behind the debt.
2. Principal in a crime: The person who directly commits a criminal act or takes part in its actual commission, as opposed to an accessory.
3. General legal usage: The chief or primary party in any legal relationship where hierarchy of obligation is at issue — the one who bears the primary duty before secondary parties are called upon.
Common Confusion
PRINCIPALIS as "principal debtor" is frequently encountered in close proximity to terms like fidejussor (surety) and guarantor, and the three are sometimes conflated. Principalis designates the primary obligor — the one from whom satisfaction must first be sought. A fidejussor or surety steps in only after the principalis has been exhausted. This hierarchy is the specific point of the maxim Principalis debet semper excuti antequam perveniatur ad fidejussores. Researchers encountering principalis in a debt or suretyship context should not read it as interchangeable with guarantor, which carries distinct modern connotations.
In criminal law contexts, principalis should be distinguished from accessory (accessorius). A principalis is present at or participates directly in the commission of the offense; an accessory assists before or after the fact but does not participate directly.
Why It Matters in Research
Principalis appears almost exclusively in Latin maxims, civil law treatises, and early common law sources. Researchers working with pre-nineteenth-century English legal materials or with sources derived from Roman and civil law traditions will encounter the term frequently without translation. Modern English sources will rarely use the Latin form — they will say "principal" — so a researcher encountering principalis in a historical document must recognize it as the Latin equivalent and trace its meaning through the maxim or doctrinal context in which it appears.
The most practically significant appearance of principalis in the corpus is within the maxim Principalis debet semper excuti antequam perveniatur ad fidejussores ("The principal should always be exhausted before coming upon the sureties"). This maxim states the civil law rule of discussion (beneficium excussionis), which required creditors to proceed against the primary debtor before turning to guarantors. This rule did not apply uniformly in early English common law and was never fully absorbed into all common law suretyship doctrines. Researchers tracing the history of guaranty, suretyship, or creditor remedies should be alert to this civil law origin and not assume the maxim states universal common law doctrine.
In criminal law materials, principalis carries a technical meaning that evolved over time. Early common law distinguished principals in the first degree (those who committed the act) from principals in the second degree (those who aided or abetted the actual commission). Both were principalis as against accessories. Modern statutes in most jurisdictions have collapsed or modified these distinctions, but the historical categories remain relevant for interpreting older indictments, judgments, and criminal law treatises.
Historical Dictionary Support
The historical dictionaries converge on the core meaning without significant divergence: principalis means principal, with its two primary applications in debt and crime. Burrill provides the most developed treatment, noting the civil law origin and the parallel term capitalis debitor (chief debtor) drawn from Fleta — a useful reminder that multiple Latin terms circulated for the same concept in early sources. Black's (both editions) and Rapalje & Lawrence carry the same substance but add the criminal law context more explicitly, with Rapalje & Lawrence providing the most detailed breakdown of first- and second-degree principals.
None of the historical sources engage meaningfully with the jurisdictional tension between the civil law rule of discussion (embedded in the principalis maxim) and common law suretyship doctrine. Researchers relying solely on dictionary treatment of this maxim may overstate its operative force in English common law contexts.
The accompanying maxim Principia data sequuntur concomitantia ("Given principles are followed by their concomitants") appears in Black's entries near the principalis entry by alphabetical proximity and is unrelated in meaning — researchers should not treat adjacency as doctrinal connection.
Jurisdictional Note
The rule embedded in Principalis debet semper excuti reflects civil law doctrine and had greater purchase in jurisdictions influenced by Roman law traditions. In English common law, the obligation to exhaust the principal before proceeding against a surety was not an absolute rule and varied by contract terms and equity. American jurisdictions diverged further, with some states codifying discussion rights and others rejecting them.