Landscape is not simply there to be perceived. People learn to interpret physical spaces as landscapes through socially shared patterns of meaning, valuation, and communication. This first volume of two introduces the foundations of landscape research from a social constructivist perspective. It reconstructs the historical development of landscape concepts, develops an analytical framework for understanding landscape, and traces the changing physical bases of appropriated landscape. It also presents major concepts and theories of landscape, ranging from essentialist and positivist perspectives to constructivist and more-than-representational approaches. By bringing together conceptual history, analytical structure, and theoretical pluralism, the volume offers a systematic introduction to the ways landscapes are constituted, interpreted, and debated. In this sense, it also provides a conceptual foundation for neopragmatist landscape research. Volume II explores current issues in landscape research and demonstrates how landscape theory can inform practical engagement.