The relation between architectural education, professional practice and theoretical investigation has with the death of Leslie Martin lost one of its driving forces. With a large number of constructions to his credit, this architect born in Manchester in 1908 divided his energy between teaching in the universities of Hull and Cambridge, technical work in his capacity as director after World War II of the architecture department of London’s County Council, and research from the center of studies on land use and built form that would later carry his name. He also spearheaded Circle, the magazine he would be co-editor of along with the painter Ben Nicholson and the sculptor Naum Gabo, and which was a prime medium for disseminating the modern ideology in postwar Britain. He wrote The Grid as Generator and his built work is compiled in Building and Ideas (1933-1983): from the Studio Leslie Martin and Associates, which also features some of his theoretical essays. In acknowledgment of his contribution, the Royal Institute of British Architects conferred on him its gold medal in 1973.