From the earliest times, human beings have been driven by the basic needs to procure food and water, shelter and defence, and communication with other members of the group. The skyscape was different from these, as it was beyond the reach of people and could not be manipulated. Yet, the innate imagination of human beings could not be unmoved by the sun and the moon, which dominate the day and night and apparently move in a well-ordered fashion, and the stars, which provide a splendid canopy on clear dark nights. Although celestial objects could not be handled and exploited in a tangible manner, people's creativity sought to understand them, to find some use for them in relation to one's needs and activities and to generate ideas about their nature and their meaning for humanity. In addition, concepts, patterns, myths and other creations of this intangible culture could be transformed into material culture, including iconography, calendars, structural orientations and other human creations. These manifestations constitute the materiality of the sky and bear witness to human beings' interest in the sky. The chapters in this volume illustrate the variety of research activity generated in this field of study across a broad spectrum of ages, cultures, and geographical regions.