Francesco de Vitoria was a Spanish theologian and philosopher born around 1483. He is often regarded as one of the founders of international law due to his ideas on natural rights and the treatment of indigenous peoples. Vitoria taught at the University of Salamanca, where he emphasized the importance of justice and morality in international relations. His work laid the groundwork for modern concepts of sovereignty and human rights. Vitoria argued that all people, regardless of their background, possess inherent rights. His writings influenced later thinkers and contributed to the development of legal frameworks governing interactions between nations.