Definition
In old English legal usage, *solidus* is a Latin term denoting a shilling — a unit of monetary account used in medieval English law to express fines, fees, land valuations, and obligations recorded in legal instruments and pleadings. The term appears in early common law texts where sums of money were stated in Latin, and *solidus* functions as the standard rendering of the shilling within that context.
The word carried no single fixed metallic equivalent across its history. In practice, when encountered in English legal sources, *solidus* means shilling: twelve pence, one-twentieth of a pound sterling in the pre-decimal system. The researcher should not read into it any particular coin but rather a unit of account with that value in the system operative at the time of the document.
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Common Language
Modern common usage (Wiktionary): In general usage, *solidus* refers primarily to the Roman gold coin introduced under Diocletian around AD 301 and reissued at slightly reduced weight by Constantine I — a high-value gold currency that became the monetary standard of the late Roman and Byzantine world. The term also encompasses its Byzantine successor coins, progressively debased from the eleventh century onward, and various medieval and early modern coins or units of account derived from or named in reference to that tradition.
Historical common usage (Webster's 1913): Webster's 1913 treats *solidus* as a historical monetary term for the late Roman gold coin, emphasizing its role as the dominant currency of the Roman and Byzantine empires.
The gap between common and legal meaning here is historically interesting and practically significant. In general historical and numismatic usage, *solidus* evokes a gold coin of substantial value — the monetary backbone of the late Roman world. In old English legal usage as Burrill records it, *solidus* means simply a shilling, a comparatively modest silver-based unit of account. The English legal usage is a downstream derivation: the shilling's abbreviation "s." and its Latin name both trace to *solidus*, but by the time the term appears in medieval English legal instruments, it had migrated entirely to denote this much smaller denomination. A researcher encountering *solidus* in a Roman law source and the same word in an English plea roll is looking at two very different monetary realities.
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Why It Matters in Research
The principal research risk with *solidus* is misreading the monetary value of a sum stated in a medieval English legal document. A researcher unfamiliar with the term's English legal meaning — or who approaches it through classical or Byzantine sources — may substantially overestimate the amount involved. In early English records, *solidus* is a shilling, not a gold coin of significant weight.
Conversely, when working with texts that bridge Roman law and English common law — as some medieval treatises do — the word may appear in both senses within related bodies of literature, requiring attention to context. Bracton and Fleta, both of which draw on Roman law frameworks, use Latin monetary terminology that can conflate traditions if read inattentively.
Fleta is directly cited by Burrill in connection with this term (lib. 2, cc. 9, 10, 11, 12), meaning researchers working in that text will encounter *solidus* as shilling in the context of valuation rules, distress, and related property matters. Coke on Littleton (Co. Litt. 294b) is the other anchor cite — a well-established reference point confirming the English legal usage.
In transcription and translation work with Latin legal manuscripts, the abbreviation "s." standing between numerals should be read as *solidus*/shilling, not as any other unit. Confusion with *denarius* (penny, "d.") and *libra* (pound, "l.") — the other two components of the £sd system — is the most common adjacent error.
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Historical Dictionary Support
Burrill's entry is brief but precise: *solidus*, in old English law, means a shilling, supported by Coke on Littleton and Fleta. Burrill does not engage with the Roman monetary history of the term, which is appropriate for a dictionary of English legal usage. What the entry does not address — and what no single English legal dictionary of that era needed to address — is the etymological and monetary chain connecting the Roman *solidus* to the English shilling. For the purposes of document research in the English common law tradition, Burrill's definition is complete and reliable.
Historical legal dictionaries generally treat *solidus* briefly as a technical Latin equivalent with no substantive content beyond the shilling identification. The more interesting scholarly territory lies in monetary history rather than legal doctrine.
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Jurisdictional Note
The English legal meaning of *solidus* as shilling is specific to the common law tradition. Researchers working in Scots law, canon law, or continental European legal sources should not assume the same usage; in Roman law texts and civilian sources, *solidus* retains its classical monetary meaning as a gold coin denomination.
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