Born in Sondrio, Italy, in 1891, Per Luigi Nervi was a pioneer in the engineering and architecture of reinforced concrete. His buildings showed how the use of reinforced concrete expanded the possibilities of form and structure. His methods, meanwhile, ingrained his structures with patterns that came directly out of his economical, manual construction processes. The results were buildings that matched awe-inspiring spans with surprisingly human scale. Beauty's Rigor offers a comprehensive overview of Nervi's long career. Drawing on the Nervi archives and a wealth of photographs and architectural drawings, Thomas Leslie explores celebrated buildings like Palazetto dello Sport built for the 1960 Rome Olympics, St. Mary's Cathedral in San Francisco, and the UNESCO headquarters in Paris. He also sheds new light on unbuilt projects such as the Pavilion of Italian Civilization for the Universal Exposition of Rome E42. What emerges is the first complete account of Nervi's contributions to modern architecture and his essential role in a revolution that realized concrete's potential to match grace with strength.