Leiden University is a public research university in Leiden, Netherlands. Founded in 1575 by William, Prince of Orange as a reward to the town of Leiden for its defense against Spanish attacks during the Eighty Years' War, it is the oldest institution of higher education in the Netherlands.
Known for its historic foundations and emphasis on the social sciences, the university came into particular prominence during the Dutch Golden Age, when scholars from around Europe were attracted to the Dutch Republic due to its climate of intellectual tolerance and Leiden's international reputation. During this time, Leiden became the home to individuals such as René Descartes, Rembrandt, Christiaan Huygens, Hugo Grotius, Baruch Spinoza and Baron d'Holbach.
The university has seven academic faculties and over fifty subject departments while housing more than 40 national and international research institutes. Its historical primary campus consists of buildings scattered across the college town of Leiden, while a second campus located in The Hague houses a liberal arts college and several of its faculties. It is a member of the Coimbra Group, the Europaeum, and a founding member of the League of European Research Universities.