Jus Gentium

Jus gentium, Latin for law of nations, was the part of Roman law that the Roman Empire applied to its dealings with foreigners, especially provincial subjects. Today the Latin term applies the body of laws that makes up international law.
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The law of nations. Although the Romans used these words in the sense we attach to law of nations, yet among them the sense was much more extended.

Some writers have made a distinction between the laws of nations which have for their object the conflict between the laws of different nations, which they call jus gentium privatum, or private international law; and those laws of nations which regulate those matters which nations, as such, have with each other, which is de nominated jus gentium publicum, or public international law.
   

This entry contains material from Bouvier's Legal Dictionary, a work published in the 1850's.