The book is the first quantitative description of Europe's economic development at a regional level over the entire 20th century. Based on a new and comprehensive set of data, this book brings together a group of leading economic historians in order to describe and analyze the development of European regions, both for nation states and for Europe as a whole. This provides a new transnational perspective on Europe's quantitative development, offering for the first time a systematic long-run analysis of national policies independently from the use of national statistical units.