Definition
Collateralis et socii (Latin: "collaterals and associates") is the ancient formal title applied to the masters in chancery — officers of the Court of Chancery who assisted the Lord Chancellor in the exercise of equitable jurisdiction. The title reflects the historical organization of the Chancery, where these officers served alongside, and in a subordinate but integral relationship to, the Chancellor. Over time, the designation fell out of use as the masters in chancery were referred to by that more functional title, and the Latin form became exclusively a historical artifact.
Why It Matters in Research
This term appears almost exclusively in pre-nineteenth-century Chancery records, treatises on equity practice, and historical treatments of English court administration. Researchers working in early equity materials — particularly English sources predating the Judicature Acts of 1873–1875, which restructured the court system and effectively abolished the old Court of Chancery as a distinct institution — may encounter collateralis et socii in formal court records, procedural manuals, or commentaries organized around Chancery offices.
The critical research trap is indexing: historical records and secondary sources that use the Latin title will not cross-reference cleanly against entries filed under "masters in chancery," and vice versa. A researcher tracing the history of Chancery officers or the development of the master's role in equity practice must search both the Latin designation and its English functional equivalent to avoid gaps.
The term also signals something about the document's era and provenance. Its presence in a source is a reliable marker of English legal practice before the consolidation reforms of the nineteenth century. American materials rarely use this form; in U.S. equity practice, the office was carried over as "master in chancery" from early colonial reception of English equity, but the Latin title did not travel with it in any systematic way.
Historical Dictionary Support
Black's Law Dictionary and Rapalje & Lawrence are in complete agreement, each defining the term identically as "the ancient title of masters in chancery." Neither source elaborates further on the structure of the office, the number of masters, or the evolution of their duties — an absence that accurately reflects the term's status as a label rather than a substantive legal concept. Both treat it as a brief glossary entry appropriate to its function: identifying what the phrase means for a reader who encounters it in old materials, without purporting to be a history of Chancery administration.
What the historical dictionaries do not address is the institutional context that gives the term meaning. The Court of Chancery developed a layered bureaucracy of officers — the Lord Chancellor at the apex, beneath him the Master of the Rolls, and then the masters in chancery proper, who handled reference proceedings, took evidence, computed accounts, and prepared reports for the Chancellor's review. The designation collateralis et socii captures the collegial, attendant character of that last group: they were lateral supporters of the Chancellor's work, not subordinate in the sense of mere clerks, but officers with defined procedural roles. Historical sources outside the legal dictionaries — particularly Spence's Equitable Jurisdiction of the Court of Chancery and early editions of Blackstone's Commentaries — are more informative on this institutional backdrop than the dictionary entries themselves.
Jurisdictional Note
This is an English legal term with no substantive American application. While the office of master in chancery was adopted in American equity courts, the Latin title collateralis et socii did not enter U.S. legal usage. Researchers working in American materials will not encounter this form; it is relevant only to English Chancery records and scholarship.