As the International Style took hold, others architects reacted to or strayed from its purely functionalist forms, while at the same time retaining highly modernist characteristics in the mid-century of modernism. Eero Saarinen, Alvar Aalto and Oscar Niemeyer were three of the most iconic architects and designers in this movement, which has influenced contemporary modernism. Architects such as Louis Kahn, Paul Rudolph, Marcel Breuer, I.M. Pei and others responded to the "light" glass curtain walls advocated by Ludwig Mies van der Rohe, by creating architecture with an emphasis on more substantial materials, such as concrete and brick, and creating works with a "monumental" quality. "Brutalism" is a term derived from the use of raw concreate,
