Refers to the early phases of the style and period that flourished in the Île-de-France with the emergence of the strong French monarchy and resulting building campaigns in the mid-12th century, and spread to other European centers. The style is characterized by a new departure from the thick supporting walls of the earlier, massive Romanesque structures to a quest for lighter, thinner, elongated proportions and greater interior illumination, using pointed arches, ribbed vaults, more open interior spaces, and enormous stained glass windows.

Source: Art and Architecture Thesaurus
http://vocab.getty.edu/page/aat/300020780