14 April 1888 – 9 April 1968, was a Swiss architectural historian and one of the central theorists of modern architecture. He studied mechanical engineering in Vienna before turning to art history, completing a doctorate in 1922 under Heinrich Wölfflin. A formative visit to the Bauhaus in 1923 and his encounter with Walter Gropius led to his lasting engagement with architectural modernism.

In 1928, he co-founded the Congrès Internationaux d’Architecture Moderne (CIAM) together with Le Corbusier and Hélène de Mandrot, serving as its first general secretary. Through extensive publications, exhibitions, and institutional initiatives, he became a key mediator of modern architecture. His influential early book Bauen in Frankreich, Bauen in Eisen, Bauen in Eisenbeton shaped the historical self-understanding of modern architects.

From 1938 to 1939, he taught at Harvard University, where his Charles Eliot Norton Lectures formed the basis of his major work Space, Time and Architecture (1941), a foundational history of modern architecture. From 1946 onward, he taught at ETH Zurich and later alternated between teaching in Switzerland and at the Massachusetts Institute of Technology. He continued to publish widely on modernity, technology, and culture until the 1960s.

Reference:
Biography text from Wikipedia (CC BY-SA), German edition. Retrieved January 19, 2026.
https://de.wikipedia.org/wiki/Sigfried_Giedion