A window provides access to two of life's essentials, light and air, but it is more than just a means to an end. Windows also have symbolic, expressive and architectural qualities that have for centuries inspired some of the world's greatest artists. In this engaging new study, Christopher Masters celebrates the multiple roles of the window in art through five key themes, from the window as a status symbol to its use as a provider of physical and spiritual illumination; from its employment as a literal window on the world outside the confines of a room to its function as a mirror, reflecting the emotions of the artist or the individuals depicted; and finally to the immense architectural variety of windows that animate interior and exterior scenes throughout Western painting. With superb reproductions of 90 works by major artists from Giotto to Banksy, and spirited analysis of the paintings' meanings, this is a remarkable exploration of an important but hitherto neglected subject in art history.