Gothic space according to Hans Jantzen and the development of stained glass windows

A change took place in stained glass window design in the late thirteenth century. The role of stained glass windows evolved between the twelfth century and late thirteenth century, from one of retaining light, as an integral part of a wall, to one of transmitting light, in the form of an architectural opening. However, this shift was relatively unappreciated in the context of cathedral spaces, given that it was overshadowed by the other architectural transformations that were taking place at the time. The aim of this work is to study this change in concept, taking the cathedral of León, Spain, as an example.