Hugo Grotius (10 April 1583 – 28 August 1645), also known as Huig de Groot, Hugo Grocio or Hugo de Groot, was a jurist in the Dutch Republic. With Francisco de Vitoria and Alberico Gentili he laid the foundations for international law, based on natural law. He was also a philosopher, theologian, Christian apologist, playwright, and poet.
Grotius's influence on international law is paramount, and is acknowledged by, for instance, the American Society of International Law, which since 1999 holds an annual series of Grotius Lectures.
In The Free Sea (Mare Liberum, published 1609) Grotius formulated the new principle that the sea was international territory and all nations were free to use it for seafaring trade. Grotius, by claiming 'free seas' (Freedom of the seas), provided suitable ideological justification for the Dutch breaking up of various trade monopolies through its formidable naval power (and then establishing its own monopoly).
England, competing fiercely with the Dutch for domination of world trade, opposed this idea and claimed That the Dominion of the British Sea, or That Which Incompasseth the Isle of Great Britain, is, and Ever Hath Been, a Part or Appendant of the Empire of that Island. William Welwod, a Scottish jurist who was the first to formulate the laws of the sea in the English language, argued against Grotius' Mare Liberum in An Abridgement of All Sea-Lawes (1613), eliciting a response from Grotius around 1615 under the title Defensio capitis quinti Maris Liberi oppugnati a Gulielmo Welwodo ("Defense of chapter five of the 'Free Oceans,' opposed by William Welwod"). In Mare clausum (1635) John Selden endeavoured to prove that the sea was in practice virtually as capable of appropriation as terrestrial territory.
As conflicting claims grew out of the controversy, maritime states came to moderate their demands and base their maritime claims on the principle that it extended seawards from land. A workable formula was found by Cornelius Bynkershoek in his De dominio maris (1702), restricting maritime dominion to the actual distance within which cannon range could effectively protect it. This became universally adopted and developed into the three-mile limit.
The dispute would eventually have important economic implications. The Dutch Republic supported the idea of free trade (even though it imposed a special trade monopoly on nutmeg and cloves in the Moluccas). England adopted the Act of Navigation (1651), forbidding any goods from entering England except on English ships. The Act subsequently led to the First Anglo-Dutch War (1652–1654).
Grotius' personal motto was Ruit hora ("Time is running away"); his last words were "By understanding many things, I have accomplished nothing."