Julio Rey Pastor (14 August 1888 – 21 February 1962) was a Spanish mathematician and historian of science. Biography Julio Rey Pastor studied high school in his hometown, and began his studies in Sciences in Vitoria. He moved to the University of Saragossa, where he found a stimulating environment in mathematics. Zoel García de Galdeano, Professor of Analytical Geometry and Calculus, was the professor who most influenced Rey Pastor’s scientific work. He graduated with honors in 1908. Rey Pastor earned his doctorate from Complutense University of Madrid in 1909, under supervision of Eduardo Torroja Caballé. Between 1911 and 1914, he studied at the University of Berlin and the University of Göttingen, under the supervision of Felix Klein. During that period, he also studied under the supervision of Professors Hermann Schwarz, Friedrich Hermann Schottky (father of Walter Schottky), and Ferdinand Georg Frobenius. His report sent to the Junta para Ampliación de Estudios (JAE) allows us to assess the significance of his studies in Germany. He especially liked Schwarz’s lectures on analytic functions and synthetic geometry, not only because of their innovations but also because Schwarz’s teaching method. In this report, Rey proposed the creation of a "seminar in mathematics to arouse the research spirit of our school children." His proposal was accepted and in 1915 the JAE created the Mathematics Laboratory and Seminar, an important institution for the development of research on this field in Spain. From 1915, Julio Rey Pastor became a dominant figure in mathematics in Spain, and later Argentina. In that year the Junta created for him in Madrid the first mathematics research institute in Spain which was outside a university. There he started a research seminar, and contributed to the advance and modernization of mathematics research and teaching. He was also the author of a series of advanced mathematics textbooks which had a very considerable influence in the Iberian world…. Undoubtedly, the creation of the laboratory was a result of Rey Pastor’s studies in Germany, and it was intended to overcome the isolation and individualism of the Spanish mathematicians. This laboratory, under the National Institute of Sciences, was first installed in the basement of the National Library, then moved to a modest apartment on Santa Teresa St., then to the building of the Center for Historical Studies and, finally, became part of the Consejo Superior de Investigaciones Científicas (CSIC), renamed Instituto Jorge Juan de Matemáticas in 1939.