The course examines 20th-century architecture in Europe and the United States, highlighting the various forms of modernity that emerged during the century: those linked to the avant-garde, as well as those resulting from the interplay between regional traditions and new architectural languages. The course will also analyze housing and urban planning reform policies and the significance of the rise of reinforced concrete. It further addresses the crisis of the Modern Movement, touching on the cutting-edge themes of the century’s final decade.