The Rights of War and Peace is a book written by Hugo Grotius on the legal status of war that is regarded as a foundational work in international law. Grotius began writing the work while in prison in the Netherlands. Its content owed much to Spanish theologians of the previous century, particularly Francisco de Vitoria and Francisco Suarez, working in the Catholic tradition of natural law.

Hugo Grotius (1583-1645) was a Dutch humanist, diplomat, lawyer, theologian, jurist, statesman, poet and playwright. Grotius was a major figure in the fields of philosophy, political theory and law during the 16th and 17th centuries. He wrote most of his major works in exile in France.