Mies van der Rohe was a renowned German-American architect known for pioneering modern architecture and popularizing the phrases "Less is more" and "God is in the details." Some of his most notable works included the Seagram Building in New York, which featured a simple rectangular form and extensive use of glass, and the Villa Tugendhat in Brno, which demonstrated his concept of fluid interior space. Mies was a master of steel and glass construction and is renowned for exposing and refining structural details to an exceptional degree, as seen in his Barcelona Pavilion which used various natural materials like marble, onyx, and glass.