Definition
De nautico fenore (Latin: "of maritime interest") is a term from Roman civil law referring to the body of rules governing interest charged on loans made for maritime ventures — principally sea loans, where repayment was conditioned on the safe arrival of the vessel or cargo. The lender bore the risk of loss at sea; in exchange, the law permitted interest rates higher than those allowed on ordinary loans. The term appears as a title heading in Roman legal texts organizing the rules applicable to this form of lending.
Why It Matters in Research
This term functions primarily as a classification label rather than a standalone doctrine. Researchers encountering it in historical sources should treat it as a pointer to the broader body of maritime loan law — specifically, foenus nauticum and the lex Rhodia — rather than as a self-contained legal concept with operative rules attached to it.
The term appears most often in texts organized around Roman civil law titles, where de nautico fenore heads a cluster of rules on maritime interest. Researchers working in admiralty history, early commercial law, or the law of bottomry will find this phrase acting as a chapter marker rather than a term of art used in pleading or adjudication. Its practical content is entirely subsumed within the related concepts listed below.
A key navigational point: because de nautico fenore is a title designation, not a cause of action or substantive rule, searching historical digests and treatises under this heading will surface the organizing category, while the operative law appears under the entries for foenus nauticum, bottomry, and respondentia. Researchers who stop at this label without following those threads will miss the substance.
The term has no continued life in modern Anglo-American law. Its relevance is exclusively historical — Roman law, early civil law jurisdictions, and the scholarly literature tracing maritime loan practices from antiquity through the medieval law merchant and into the development of bottomry bonds in English admiralty practice.
Historical Dictionary Support
Burrill's Law Dictionary defines the term tersely: "Of maritime interest. A title of the civil law." This entry is accurate but minimal — it correctly identifies the term as a Roman law title designation rather than inflating it into something more. Burrill does not attempt to synthesize the substantive rules or trace their reception into English law, which is consistent with his treatment of Latin titles generally.
Historical sources on this topic that go beyond Burrill include Justinian's Digest (Book 22, Title 2, "De nautico fenore"), which contains the primary texts, and later civilian commentators who elaborated on the permissible rates of maritime interest and the allocation of sea risk. Scholars working on the history of insurance and maritime commerce — Sanborn, Holdsworth, and others writing on admiralty history — provide the connective tissue between Roman practice and the bottomry bond tradition in English law.
What historical dictionaries as a class tend to understate is the economic significance of the concept: the willingness of Roman law to exempt maritime loans from ordinary usury limits was a foundational move in the history of commercial finance, enabling risk-allocation mechanisms that prefigure modern marine insurance.