Definition
CONQUEST carries distinct meanings in feudal law and international law, each operating on entirely different principles.
1. Feudal law. Any acquisition of an estate by means other than inheritance or descent — that is, by purchase, grant, gift, or any act of the party rather than operation of law. An estate so acquired was called an estate of conquest, as distinguished from an estate of inheritance. The term was not limited to forcible taking; a simple conveyance by sale was a "conquest" in this sense. This usage was prominent in Scots law and in older English feudal doctrine.
2. International law. The acquisition of sovereignty over a foreign territory through military force, by which a conquering state reduces the defeated state or population to submission and asserts dominion over the territory. Under classical international law, conquest followed by subjugation and annexation could transfer title to territory. This principle has been substantially curtailed in modern international law, particularly following the United Nations Charter and twentieth-century treaty frameworks prohibiting the acquisition of territory by force.
Common Language
Modern common usage (Wiktionary): To compete with an established competitor by placing advertisements adjacent to content relating to that competitor, or by using keywords associated with a competitor's products. (This is a specialized marketing term and an outlier definition.)
Historical common usage (Webster's 1913): The act or process of acquiring by force; the act of overcoming opposition by force, whether physical or moral; subjection; victory. Also, that which is conquered; possession gained by force.
The gap matters. The ordinary historical meaning of conquest — forcible subjugation — maps onto only one of the two legal meanings. The feudal law usage inverts this entirely: a peaceful purchase of land was a "conquest." Researchers encountering the word in feudal property texts and assuming it signals military or forcible taking will misread their sources. The modern marketing usage has no legal relevance and should be disregarded entirely.
Common Confusion
Two confusions recur in research.
First, readers conflate the feudal and international law meanings. In a feudal property context, conquest means acquisition by any means other than descent — it is essentially synonymous with purchase. In an international law context, conquest means forcible subjugation of a foreign territory. These are near-opposites in connotation and must not be imported across contexts.
Second, Burrill's notes that some early commentators objected to efforts to give the word "acquisition in a feudal sense" as a distortion of its natural meaning. This tension was a live dispute among nineteenth-century legal lexicographers and surfaces in period treatises and annotations. A researcher reading an older commentary criticizing the "conquest" usage should understand this as a doctrinal debate about terminology, not an error in the primary source.
Why It Matters in Research
Feudal property research: The feudal meaning of conquest appears throughout early English and Scots land law materials and in Blackstone's commentaries. Researchers working with older conveyancing materials, feudal tenure records, or Scots property law must treat conquest as a term of art meaning purchase or non-hereditary acquisition. The word will appear in contexts that make no sense if read as military subjugation.
International law research: The conquest doctrine was operative international law through the nineteenth and into the early twentieth century. Cases involving land grants derived from prior sovereigns — particularly in post-colonial and post-annexation American litigation — frequently engage conquest doctrine to assess the validity of title. Castillero v. United States, cited in Black's 2nd edition, is an example of conquest doctrine arising in American federal court in the context of Spanish land grants following the Mexican-American War. Researchers must be alert to whether a source is applying conquest doctrine as it stood at the time of the relevant events, not as it stands today.
Twentieth-century shift: Modern international law has largely repudiated conquest as a valid basis for territorial acquisition. The Stimson Doctrine (1932), the UN Charter (Article 2(4)), and subsequent UN resolutions (particularly UN General Assembly Resolution 2625 of 1970) progressively dismantled the legal validity of conquest. Sources predating these developments treat conquest as a legitimate root of title; post-1945 sources increasingly treat it as void. This temporal split is a major trap for researchers synthesizing across periods.
Scots law: In Scottish legal materials, conquest is routinely used to mean purchase, following the civil law tradition. Bell's Dictionary (referenced in Black's) uses it in exactly this sense. Researchers working in comparative law or Scottish legal history should not be surprised by this usage.
Historical Dictionary Support
Black's (1st and 2nd editions) and Burrill's agree on the core dual structure: feudal acquisition by non-descent means, and international law subjugation by force. All three sources treat these as parallel definitions under a single headword without suggesting they share conceptual common ground — which is accurate.
Burrill's provides the most useful historical texture, flagging the lexicographic controversy over importing the feudal meaning and noting Wharton's skepticism of that usage. This signals that even in the nineteenth century, the feudal meaning was contested as a matter of terminology, though not as a matter of doctrine.
What the historical dictionaries miss: None of the shelf sources address the twentieth-century collapse of conquest as a valid basis for title in international law. For any research touching the post-1945 period, these entries are incomplete and must be supplemented with international law sources. They also do not address the specifically American context of conquest doctrine in relation to Native American land title, where a distinct line of case law — drawing on but modifying classical conquest doctrine — developed separately.
Jurisdictional Note
In United States law, conquest doctrine has particular resonance in cases involving land title derived from prior sovereigns (Spanish, French, Mexican, British) and in the separate body of federal Indian law, where conquest has been used as a foundational concept in ways that diverge significantly from classical international law usage. Researchers should treat these as related but distinct doctrinal streams.