1583 – 1645
Hugo Grotius (1583–1645) was a Dutch jurist, philosopher, and theologian widely regarded as the father of international law. His landmark work De Jure Belli ac Pacis (1625) systematized natural law theory and laid the foundations for modern international legal order. He also made significant contributions to Arminian theology and was a key figure in early modern efforts to reconcile Christian denominations.
Founded modern international law through De Jure Belli ac Pacis (1625)
Articulated the doctrine of mare liberum (freedom of the seas) in Mare Liberum (1609)
Developed a secular natural law theory grounded in rational human nature rather than divine command
Advanced early theories of just war and the rights of nations in conflict
Contributed to Arminian theology and ecumenical Protestant thought