International Law Definition: A combination of treaties and customs which regulates the conduct of states amongst themselves, and persons who trade or have legal relationships which involve the jurisdiction of more than one state. Related Terms: Will, Holograph Will, State The highest judicial authority of international law is the International Court of Justice and the administrative authority is the United Nations. John Bassett Moore was a well-known international law jurist and graduate from the University of Virginia law school in 1880, long-time professor at Columbia University, and one of the first to be appointed justice of the then-newly formed Permanent Court of International Justice in 1921. He defined international law as follows: "A body of rules common to all civilized nations, equally binding upon all and impartially governing their mutual intercourses." REFERENCES: Duhaime, Lloyd, International Law - A Primer. Moore, John Bassett, Digest of International Law, 8 volumes (1898) Categories & Topics: International Law Dictionary Find you are constantly looking up definitions? Try our search provider (works in most modern browsers) If you find an error or omission in Duhaime's Legal Dictionary, or if you have legal term suggestion, we'd love to hear from you!