jus gentium privatum

Jus gentium privatum is a Latin term that translates to "private law of nations" and is synonymous with private international law, also known as the conflict of laws. This area of law deals with cases involving foreign elements, determining which country's laws should apply when there's a dispute between individuals or entities from different nations.123

Historically, jus gentium (law of nations) was developed by Roman lawyers to create a system of equity applicable to cases involving both Roman citizens and foreigners. It was based on the idea that rules of law common to all nations must be fundamentally just. Over time, jus gentium became a flexible alternative to the more rigid jus civile (civil law) that applied only to Roman citizens. By the 3rd century CE, the distinction between jus civile and jus gentium largely disappeared as Roman citizenship was extended throughout the empire.14