Jus gentium

In Roman law and legal traditions influenced by it, ius gentium or jus gentium (Latin for "law of nations" or "law of peoples") is the law that applies to all gentes ("peoples" or "nations"). It was an early form of international law, comprising not a body of statute law or legal code, but the customary law thought to be held in common by all in "reasoned compliance with standards of international conduct". Ius gentium was regarded as a form of ius naturale, or natural law. Unlike ius civile, it applied to all persons and not only Roman citizens, as the rules of ius gentium could be derived from natural reason as innate in all of mankind. Following the Christianization of the Roman Empire, canon law also contributed to the European ius gentium. By the 16th century, the shared concept of the ius gentium disintegrated as individual European nations developed distinct bodies of law, the authority of the Pope declined, and colonialism created subject nations outside the West.