The savagery displayed by all participants in the Thirty
Years' War could not but impress thinking men with the necessity of formulating
rules to protect noncombatants, to care for prisoners, and to do away with
pillage and massacre. The worst horrors of the war had not taken place, before
a Dutch jurist, named Hugo Grotius, published at Paris in 1625 A.D. a work On
the Laws of War and Peace. It may be said to have founded international
law. The success of the book was remarkable. Gustavus Adolphus carried a copy
about with him during his campaigns, and its leading doctrines were recognized
and acted upon in the Peace of Westphalia.
THE EUROPEAN STATE SYSTEM
The great principle on which Grotius based his
recommendations was the independence of sovereign states. He gave up the
medieval conception of a temporal and spiritual head of Christendom. The
nations now recognized no common superior, whether emperor or pope, but all
were equal in the sight of international law. The book of Grotius thus marked
the profound change which had come over Europe since the Middle Ages.
