Ludwig Mies van der Rohe (1886-1969).In addition to being one of the most significant and influential architects of the 20th century, Ludwig Mies van der Rohe is considered the most rigorous of the Rationalists, with his pure, perfectly geometric spaces, organized on planes freed of the restrictions of walls. Born in Aquisgrana, he studied and worked as a furniture designer in Berlin, coming into contact with Gropius and Le Corbusier. He later remained fascinated by the works of Wright. When he opened his own architecture studio, his work began to draw closer to the De Stijl movement and Constructivism, and he started designing using steel and glass, extremely innovative elements for the time. Vice-president of the Werkbund, a cultural organization of primary importance in the '30s, he also served as director of the Bauhaus. Among the main European projects are the Weissenhof building in Stuttgart, Villa Tugendhat in Brno, and the German pavilion for the 1929 International Exposition of Barcellona. In 1937 he moved to the United States, where he was appointed Dean of the Faculty of Architecture at the Institute of Technology of Chicago, dedicating his efforts, among many other things, to the building of skyscrapers, defining continuously new and functional designs.