This introduction presents an overview of the concepts covered in this book. It sketches the growing knowledge about the world's appearance and the largely civilization-centric works of history that were available during the Middle Millennium. Maps are apt to traverse civilizational boundaries with relative ease. The chapter explores the history of the Middle Millennium as it emerges from present-day research. It discusses cartography, written histories, and regular trans-civilizational relations. Pride of place in the study of the movement toward more intense integration of large-area units, and of communication among them, should go to regular interactions. Of these, the most important were war and conquest that led to the formation of states, the development of trade networks, and the emergence of religious ecumenes. The spread of paper exemplifies the ways in which knowledge and technology spread and how an item could be detached from its original major use as it spread.