Hugo Grotius was a Dutch jurist, philosopher, and statesman who lived from 1583 to 1645. He is widely regarded as one of the founders of international law, most notably for his influential work "De Jure Belli ac Pacis" (On the Law of War and Peace), published in 1625. Grotius made significant contributions to natural law theory and social contract theory, and his writings laid important foundations for modern concepts of international relations and diplomacy.