Book excerpt: This book explores various ways of identifying and understanding the character of historic townscapes from a systematic and comparative perspective. It outlines several genetic approaches to the study of urban form, grounded in the traditions of geographical analysis but wholly interdisciplinary in their content and implications. It develops a philosophical and methodological basis for the field of urban morphology, stressing the reciprocal relations between town plan, building fabric and land and building utilisation. It views these elements as spatially variable accumulations and selective survivals of forms regulated by shifting patterns of corporate and individual decisions made from one historical period to another - in perpetual tension between resistance and change. Several of the essays in this collection establish and exemplify conceptual principles and axioms of urban morphological development in historic towns, and introduce numerous specific processes by which built forms are created and juxtaposed in urban space. Other essays apply these precepts by interpreting a number of case studies of historic towns in Britain, Germany, Japan, New Zealand and elsewhere. The closing essay offers a unique interpretation of the regional varieties to be found in medieval European urbanism, based on differing traditions of social formation and morphological outcomes.