"Others wrote upon the law of nations before him, but Grotius was the first to attempt a systematic treatise. . . . In his De Jure Belli ac Pacis, first published in 1625, there is precedent or inspiration for most of the important doctrines elaborated by later writers." -- Edwin D. Dickinson, 26 American Journal of International Law 239 (1932)
Hugo Grotius [1583-1645] a pre-eminent contributor to international legal doctrine, was an influential Dutch jurist, philosopher, and theologian. De Jure Belli ac Pacis (On the Law of War and Peace), originally published in 1625, is widely considered to be the first master treatise on international law. Grotius is also known for De Jure Praedae (1604), in which he argues against territorial sovereignty of the seas, and The Freedom of the Seas (Mare Liberum) (1609), which continues his plea for free trade among all nations.