This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book describes responsible innovation in terms of both the innovation process and the innovation outcome, and in doing so it focuses on historical cases of innovation in large societally relevant technological systems. It illustrates how responsible innovation can be defined by discussing how it is applied or can be applied in specific cases of societally relevant large technological systems. The book focuses on large societally relevant, technological systems, most contributions take a systems perspective in which social and technological aspects are explored in combination. It explores how responsible the innovation process was during three episodes of wind power development: the American farm windmill between 1850 and 1880 in the USA, the direct current electricity wind turbine between 1890 and 1910 in Denmark, and the alternating current electricity wind turbine between 1940 and 1990 in the USA.