Feudal Law. This term was used by the feudists to signify purchase.
International Law. The acquisition of the sovereignty of a country by force of arms, exercised by an independent power which reduces the vanquished to the submission of its empire.
It is a general rule that where conquered countries have laws of their own, these laws remain in force after the conquest, until they are abrogated, unless they are contrary to our religion, or enact any malum in se. In all such cases the laws of the conquering country prevail; for it is not to be presumed that laws opposed to religion or sound morals could be sanctioned.
The conquest and military occupation of a part of the territory of the United States by a public enemy renders such conquered territory, during such occupation, a foreign country with respect to the revenue laws of the United States. The people of a conquered territory change their allegiance, but by the modern practice, their relations to each other and their rights of property remain the same.
Conquest does not, per se, give the conqueror plenum dominium et utile, but a temporary right of possession and government.
The right which the English government claimed over the territory now composing the United States was not founded on conquest, but discovery.