Steel is one of the most important building materials of our time and is closely related to notions of “modern” construction or modern architecture in general. This book aims not only to illustrate the beginnings of steel’s usage as a building material, it also endeavors to show the theoretical, practical, formal, and cultural consequences of these beginnings 200 years ago. The volume critically looks at the many-layered connections between architecture and engineering and at the dramatically changing way in which the disciplines understand themselves. All of this is contextualized by examining the usage of iron, the new structural building material, during the industrialization period. For this purpose, many notable authors from various disciplines contribute their view.