Definition
In historical maritime and international law, "pat" is an abbreviation for "pass" or "patent pass" — a document issued to vessels by governmental authority granting protection or safe conduct. The term appears in two principal legal contexts:
1. Mediterranean Pass (or Mediterranean Pat): A document issued under governmental authority to American merchant vessels as protection against seizure by the Barbary powers of North Africa. The pass served as formal notice of nationality and official protection, functioning as a credential of neutral or protected status on the high seas.
2. War Pass / Safe Conduct: A permission granted during wartime authorizing the holder — whether a person or a vessel — to travel through or depart from hostile territory, or to engage in otherwise prohibited intercourse with the enemy. Such a pass operated as a temporary dispensation from the legal consequences of war, suspended to the extent and duration specified in the instrument.
Common Language
Modern common usage (Wiktionary): An Irish person; also, a light tap or stroke with the hand.
Historical common usage (Webster's 1913): To strike gently with the fingers or hand; to stroke lightly; to tap.
The legal use of "pat" as a pass or safe-conduct document bears no relationship to either common meaning. Researchers encountering "pat" in historical maritime records or legal pleadings should treat it as a document-of-protection term, not a reference to a gesture or a nationality.
Common Confusion
"Pat" in this legal sense is easily confused with "patent" (an exclusive grant of rights) or overlooked entirely as a typographical abbreviation. In older sea-law records, "pat" frequently appears as a shortened form of "passport" or "pass," and its legal significance as a formal instrument of protection can be missed when the context is not maritime. Do not conflate with letters of marque, which authorize offensive action, or with bills of health, which certify a vessel's sanitary status at departure.
Why It Matters in Research
Researchers working in historical maritime law, prize law, or the law of war will encounter "pat" as an abbreviated form in ship's papers, admiralty court records, and international law treatises of the eighteenth and early nineteenth centuries. The term is particularly relevant to the period of American engagement with the Barbary States (roughly 1794–1815), when Mediterranean passes were issued under federal authority. Because the word is also common English, full-text searches across digitized historical sources will generate enormous noise. Narrowing searches to maritime, admiralty, or prize law contexts — or pairing the term with "Mediterranean," "safe conduct," or "Barbary" — will sharply improve precision.
The dual function of the term (vessel protection in peacetime commerce versus personal safe conduct in wartime) means that the same word can describe instruments with meaningfully different legal consequences and issuing authorities. Researchers should identify which context applies before drawing conclusions about the legal effect of a particular instrument.
Historical Dictionary Support
Burrill's Law Dictionary is the principal historical dictionary source for this term and treats it primarily in its maritime dimension, pointing readers to Jacobsen's Sea Laws for the mechanics of the Mediterranean pass and to Kent's Commentaries for the wartime safe-conduct function. Burrill's entry is brief and derivative, synthesizing rather than analyzing.
What historical dictionaries miss: There is no sustained treatment in standard historical legal dictionaries of the procedural requirements for a valid pat/pass, the consequences of traveling without one, or the adjudication of prize cases turning on the presence or absence of such a document. Researchers needing that depth should move directly to Jacobsen's Sea Laws and Kent's Commentaries, Vol. 1, and to admiralty court records of the relevant period.
Jurisdictional Note
The Mediterranean pass was a creature of American federal law and practice, distinct from similar instruments issued by European naval powers. The wartime safe-conduct function was recognized across European international law generally, but the specific form, issuing authority, and legal effect varied by nation and treaty. Research across jurisdictions requires caution about assuming equivalence between instruments bearing similar names.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Safe Conduct; Maritime Law; Prize Law; Barbary Treaties