Definition
A gold coin of English origin, first struck during the reign of King James I (1603–1625), from whom it takes its name. The jacobus carried a face value generally stated at twenty-four to twenty-five shillings sterling. In legal and commercial documents from the seventeenth century onward, the term appears most often when courts, contracts, or estate records denominate sums in the coin that was current at the time of transaction or bequest.
Common Language
Modern common usage (Wiktionary): A former English gold coin from the Jacobite period.
Historical common usage (Webster's 1913): An English gold coin of the value of twenty-five shillings sterling, struck in the reign of James I.
The common usage here tracks closely to the legal one, but with a notable divergence in context: the ordinary language definitions treat the jacobus as a numismatic curiosity, while legal sources encounter it as a unit of account in historical instruments. The researcher's task is not definitional but computational — converting a stated sum in jacobuses into its contemporary sterling equivalent when construing the operative effect of an old document.
Common Confusion
Two related confusions arise in legal research. First, the jacobus is distinct from the guinea (21 shillings), the sovereign, and the broad-piece, though Bouvier notes that "broad," "laurel," and "broad-piece" were alternative names for the same coin in some usage. Second, the valuation is not uniform across sources: Black's both editions state 24 shillings; Webster's and Bouvier state 25 shillings; and Bouvier cites Macaulay's History of England, chapter XV, for an implied rate that resolves to approximately 25 shillings (eight thousand jacobuses equaling ten thousand pounds sterling). The discrepancy is not trivial when large sums are at issue in an old estate or commercial dispute.
Why It Matters in Research
The jacobus surfaces almost exclusively in historical legal materials — seventeenth and eighteenth-century English wills, lease agreements, commercial contracts, and occasionally colonial American instruments that carried English monetary conventions. Researchers encounter the term most often when interpreting the financial terms of an old document rather than as a substantive legal concept in its own right.
Key navigational points:
The valuation problem is the practical issue. Bouvier's Macaulay reference provides the most explicit conversion anchor (8,000 jacobuses = £10,000 sterling), suggesting a 25-shilling standard. When Black's 24-shilling figure is used instead, the same 8,000 coins would equal only £9,600. For large sums, the choice of rate matters and should be flagged explicitly in research memos.
Colonial corpus: American legal instruments occasionally denominated sums in jacobuses through the mid-eighteenth century, particularly in mid-Atlantic colonies with strong English mercantile ties. When reading pre-revolutionary estate inventories or mercantile contracts in the Law Mind corpus, the term may appear alongside pistoles, moidores, and other foreign gold coins — all of which create the same conversion problem.
Not a term of art: The jacobus carries no legal doctrine attached to it. It is a monetary denomination, and its appearances in legal sources are purely descriptive or quantitative. Research time should not be spent on the term itself but on understanding the document's financial structure in context.
Historical inflation and purchasing power: Any analysis of the real-world significance of a sum stated in jacobuses requires attention not only to the shilling conversion but to seventeenth-century purchasing power. Standard economic history tools (such as the long-run series compiled by economic historians of early modern England) are necessary supplements to the legal dictionaries alone.
Historical Dictionary Support
The three source dictionaries agree on the essential identification — a gold coin named for James I — but diverge on value and detail.
Black's (both editions) is the most spare: 24 shillings, with the note "Enc. Lond." (Encyclopaedia Londinensis) as authority. No alternative names are given and no conversion anchor is provided.
Bouvier is the most useful for legal research. It supplies the coin's physical dimensions (one inch and three-eighths in diameter), its alternative names (broad, laurel, broad-piece), and — most valuably — the Macaulay conversion figure. Bouvier also notes the valuation dispute directly, acknowledging both the 24- and 25-shilling figures without resolving it, which is an honest reflection of the historical ambiguity.
Webster's 1913 states 25 shillings and agrees with Bouvier's implied Macaulay rate.
What the historical dictionaries miss: None of the three addresses the jacobus's appearance in American colonial instruments, nor do they provide guidance on how a court or researcher should handle the valuation discrepancy when construing an old document. The dictionaries treat the term as settled fact; the practical research problem is that it is not entirely so.
Jurisdictional Note
The jacobus is an English coin and its legal appearances are almost entirely in English or English-derived legal documents. American courts occasionally encountered jacobus-denominated instruments in early colonial and post-colonial estate litigation, but no distinct American legal treatment of the coin developed.