The Basilica of St Denis is an architectural landmark as it was the first major structure of which a substantial part was designed and built in the Gothic style. Both stylistically and structurally it heralded the change from Romanesque architecture to Gothic architecture. Before the term "Gothic" came into common use, it was known as the "French Style" (Opus Francigenum). As it now stands, the church is a large cruciform building of "basilica" form, that is, it has a central nave with lower aisles and clerestory windows. It has an additional aisle on the northern side formed of a row of chapels. The west front has three portals, a rose window and one tower, on the southern side. The eastern end, which is built over a crypt, is apsidal, surrounded by an ambulatory and a chevet of nine radiating chapels. Abbot Suger (circa 1081-1151), friend and confidant of the French kings Louis VI and Louis VII, decided in about 1137 to rebuild the great Abbey Church of St Denis, attached to an abbey which was also a royal residence. Suger began with the West front, reconstructing the original Carolingian façade with its single door. He designed the façade of St Denis to be an echo of the Roman Arch of Constantine with its three-part division and three large portals to ease the problem of congestion. There is a rose window above a west portal. Although circular windows in this position were common in Italian Romanesque churches, it is believed to be the first rose window in this position in France, and was to become a dominant feature of the Gothic facades of northern France, soon to be imitated at Chartres Cathedral and many others.[3] At the completion of the west front in 1140, Abbot Suger moved on to the reconstruction of the eastern end, leaving the Carolingian nave in use. He designed a choir (chancel) that would be suffused with light. To achieve his aims, Suger's masons drew on the several new features which evolved or had been introduced to Romanesque architecture: the pointed arch, the ribbed vault, the ambulatory with radiating chapels, the clustered columns supporting ribs springing in different directions and the flying buttresses which enabled the insertion of large clerestory windows.

The north transept rose shows the Creation. It was the first time that these features had all been drawn together. Erwin Panofsky argued that Suger was inspired to create a physical representation of the Heavenly Jerusalem, however the extent to which Suger had any aims higher than aesthetic pleasure has been called into doubt by more recent art historians on the basis of Suger's own writings. The new structure was finished and dedicated on June 11, 1144, in the presence of the King.[4] The Abbey of St Denis thus became the prototype for further building in the royal domain of northern France. From 1231 the old nave of St Denis was rebuilt, introducing the new Rayonnant Gothic style, and gaining, in its transepts, two spectacular rose windows.[5] Through the rule of the Angevin dynasty, the style was introduced to England and spread throughout France, the Low Countries, Germany, Spain, northern Italy and Sicily.[6][7]