[4][5][6] He received a degree in architecture from the Polytechnic University of Milan in 1936, and subsequently went into practice with his brother Pier Giacomo and Luigi Caccia Dominioni.

[4] Much of the early work of the Castiglioni brothers was in exhibition design, although they also carried out a number of architectural projects, including the reconstruction in 1952–1953 of the Palazzo della Permanente [it] in Milan, which had been destroyed by Allied bombing in 1943.

– Phonola [it] 547" tabletop radio, which is amongst the earliest examples of this product typology to challenge traditional shapes and aesthetics, making it a turning point in the history of Italian industrial design.

[18][19][better source needed] Working as a lighting designer throughout the 1960s and 1970s Castiglioni collaborated with many of his contemporaries such as the architects Gae Aulenti, Cini Boeri, Cesare Maria Casati [it] and Roberto Menghi [it], as well as his son Piero [it].

They were the Castiglioni, like their work, indivisible fruit of the same research, of the same passion, of a great ability to transform the world around us into a new memorable gesture.