On completion of the west front, Abbot Suger moved on to the reconstruction of the eastern end, leaving the Carolingian nave in use.
 He wanted a choir (chancel) that would be suffused with light.
To achieve his aims, Suger's masons drew on the several new elements which evolved or had been introduced to Romanesque architecture: the pointed arch, the rib 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.

It was the first time that these features had all been drawn together, and the style evolved radically from the previous Romanesque architecture by the lightness of the structure and the unusually large size of the stained glass windows.

The new structure was finished and dedicated on 11 June 1144, in the presence of the King.
The Abbey of St Denis thus became the prototype for further building in the royal domain of northern France.
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.
On completion of the west front, Abbot Suger moved on to the reconstruction of the eastern end, leaving the Carolingian nave in use.  He wanted a choir (chancel) that would be suffused with light. To achieve his aims, Suger's masons drew on the several new elements which evolved or had been introduced to Romanesque architecture: the pointed arch, the rib 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.
It was the first time that these features had all been drawn together, and the style evolved radically from the previous Romanesque architecture by the lightness of the structure and the unusually large size of the stained glass windows. 
The new structure was finished and dedicated on 11 June 1144, in the presence of the King. The Abbey of St Denis thus became the prototype for further building in the royal domain of northern France. 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.
Basilica of Saint-Denis