The importance of Eugène-Emmanuel Viollet-le-Duc (1814-1879) within modern architecture cannot be overstated. Key theoretician of modernism, renowned restoration architect, medieval archaeologist and champion of Gothic revivalism, he also published some of the most influential texts in the history of modern architecture. Martin Bressani expertly traces Viollet-le-Duc’s complex intellectual development, showing how restoration, in all its layered meaning, shaped his outlook. Through his life journey, we follow the route by which the technological subject was born out of nineteenth-century historicism.