Hundreds of these great churches were built throughout Europe in a rich variety of styles between c. 1130 and c. 1530, all of them representing an investment of money and effort so immense that it is difficult to find a modern parallel. Christopher Wilson focuses here on the interaction between design and the requirements of patrons, following the creative processes of architects by reconstructing the problems and opportunities that they faced. He discusses chronology, structural techniques, and stylistic developments and then goes further, seeing the story as a sequence of choices from which new challenges and solutions arose. 221 illustrations.