Definition
Latin: "on account of defect of blood." A ground for the escheat or forfeiture of property to the crown or state arising from the failure of heritable blood — that is, the absence of any lawful heir capable of taking by descent. Where a person died without heirs of the blood legally qualified to inherit, the property did not pass by succession but instead escheated, typically to the lord of the fee or, later, to the state. The defect referred to is not a physical or mental condition but a genealogical one: the bloodline, for purposes of inheritance, has run out or is legally disqualified.
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Common Confusion
The phrase is easily confused with *propter defectum mentis* or general incapacity grounds used to challenge jurors or parties to legal proceedings. Those uses concern mental or personal fitness; *propter defectum sanguinis* is exclusively a concept of the law of descent and escheat. The term should not be read as suggesting any deficiency in a living person — it describes the legal status of a bloodline relative to a particular inheritance.
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Why It Matters in Research
This term appears almost exclusively in historical sources dealing with feudal tenure, the law of descent, and escheat doctrine. Researchers encounter it most often in:
1. **Escheat proceedings and treatises on real property tenure.** The term marks the boundary between inheritance by descent and reversion to the sovereign. In American sources, the feudal vocabulary survived well into the nineteenth century in treatises even as the underlying doctrine was being reshaped by statute. Where you see *propter defectum sanguinis* in an American source, the writer is almost certainly drawing on Blackstone or earlier English authority, often without updating the analysis for post-revolutionary or post-Reconstruction statutory reforms.
2. **Failure of issue.** Rapalje & Lawrence cross-reference this term directly to FAILURE OF ISSUE, which is the more commonly encountered phrase in nineteenth-century American legal materials. Researchers should follow that cross-reference: the operative doctrine in most American jurisdictions was reorganized under the language of "failure of issue" and later statutory provisions governing intestate succession, making the Latin phrase largely a citation anchor to older authority rather than a working legal standard.
3. **Alien disability doctrine.** Historically, *propter defectum sanguinis* also encompassed the incapacity of aliens to transmit or receive real property by descent — a "defect of blood" in the sense that alien blood was not heritable blood at common law. This application of the phrase has particular importance in researching nineteenth-century property disputes involving naturalization status, and researchers should be alert to whether a source is using the term in its pure escheat-for-want-of-heirs sense or in its alien-incapacity sense.
4. **Jury challenge research.** There is a distinct but related Latin formula — *propter defectum* standing alone — used in challenge-to-the-array or challenge-to-the-poll doctrine to denote challenges based on some legal disqualification of a juror. The *sanguinis* element removes the phrase from that context entirely, but researchers pulling Latin maxims from indexes should confirm the full phrase before applying the definition.
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Historical Dictionary Support
Rapalje & Lawrence identify the phrase as meaning "on account of failure of blood" and direct the reader to FAILURE OF ISSUE. This cross-reference is the entry's primary substantive content, reflecting how mid-to-late nineteenth-century American legal lexicography treated the term: as a Latin label for a doctrine already being handled under English-language terminology in practice. The historical dictionaries do not elaborate on the alien-incapacity dimension of the term, which was being eroded by naturalization statutes at the time most of these dictionaries were compiled and may therefore be underrepresented in those sources relative to earlier treatise literature. Blackstone's *Commentaries* (Book II) and Littleton's *Tenures* remain the authoritative primary sources for the full technical scope of the phrase; researchers should not rely on nineteenth-century American dictionary entries alone for the feudal law background.
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Jurisdictional Note
American states abolished or substantially modified the common law of escheat *propter defectum sanguinis* through intestate succession statutes, many enacted in the nineteenth century. The phrase retains relevance in historical title research, particularly for chains of title predating comprehensive intestacy legislation, but has no operative modern application in American law outside of historical analysis.
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