Definition
A Latin term meaning "of those who are to be put on assises." In legal usage, SISIS refers specifically to the short title of a statute enacted during the reign of Edward I (21 Edward I) that established formal qualifications for jurors serving on assises. The statute defined who was eligible to be summoned and seated as a juror in assize proceedings, setting property, residency, or other fitness criteria that a prospective juror was required to meet.
Common Confusion
SISIS is sometimes loosely grouped with the broader body of Edwardian procedural legislation, but it is a discrete statute with a specific and narrow purpose: juror qualification. It should not be confused with the Statute of Westminster (either the First or Second), which addressed a wider range of procedural and substantive reforms during the same reign, nor with the Assize of Novel Disseisin or other named assises, which were forms of action rather than administrative enactments governing jury composition.
Why It Matters in Research
Researchers encountering SISIS in historical legal texts are most likely working in one of two contexts: the history of English jury law, or the administrative machinery of the medieval assize system. A few navigational points deserve attention.
First, the term appears almost exclusively in historical and antiquarian legal sources. It will not appear in modern statutory compilations or contemporary legal practice materials. Researchers should treat any citation to SISIS as a signal that they are operating within medieval English legal history, specifically the late thirteenth century.
Second, the statute's significance lies in what it represents structurally: an early formal effort to regulate jury composition by statute rather than by judicial discretion or local custom. For researchers tracing the development of jury qualification requirements — property thresholds, residency requirements, oath capacity — SISIS is a starting point in that documentary lineage. Later English statutes and eventually colonial and American jury qualification rules descend, conceptually if not always directly, from this tradition of legislatively fixed eligibility criteria.
Third, researchers should be aware that the statute is typically accessed through secondary historical sources rather than through a modernly annotated primary text. The standard references are Crabb's History of English Law and Reeves' History of English Law, both of which are present in the Law Mind corpus. Cross-checking both is advisable, as pagination references in Burrill and Black differ slightly between the two works, reflecting different editions in circulation.
Fourth, the assize system itself was abolished in England by the Courts Act 1971, which replaced assizes and quarter sessions with the Crown Court. SISIS is therefore a term of purely historical rather than operational legal significance in any contemporary jurisdiction.
Historical Dictionary Support
Burrill's Law Dictionary and Black's Law Dictionary (2nd Ed.) are in close agreement on this entry, with Black's essentially condensing Burrill's language. Both identify the statute as 21 Edward I and describe its subject matter — juror qualifications for assises — in identical terms. Both cite Crabb's History of English Law and Reeves' History of English Law as the supporting secondary authorities, though the page references vary modestly between the two entries, likely reflecting different printings of those works.
Neither dictionary elaborates on the substance of the qualifications the statute imposed, the enforcement mechanism, or the historical context of jury reform under Edward I more broadly. Researchers needing that substantive detail must turn directly to Crabb or Reeves rather than relying on these dictionary entries as anything more than a locating tool.
It is worth noting that neither Black's nor Burrill treats SISIS as part of a larger family of related statutes, though Edward I's reign was exceptionally productive legislatively. The entry functions in both dictionaries as a stand-alone definitional reference, appropriate given how narrowly the term operates.
Jurisdictional Note
SISIS is a statute of medieval English law with no direct counterpart in Scots law, Irish law, or any American jurisdiction. Its relevance is confined to the history of English common law. Researchers working in American legal history may encounter its influence only indirectly, through colonial-era and early state jury qualification statutes that drew on the English common law tradition of legislatively defined juror eligibility.