Sep Ruf is regarded as one of the most important German architects of the 20th century. With his elegant, transparent buildings, such as the German pavilion at the 1958 World Fair in Brussels (with Egon Eiermann) or his "Kanzlerbungalow" in Bonn, he not only exerted considerable influence on modern German post-war architecture, but helped shape the image of the young republic in the world. Being the first to present and analyze Ruf 's oeuvre as a whole, this publication seeks to re-evaluate and assess its place in the history of architecture