A Gothic chapel added in the mid-13th century is noted as a smaller-scale reinterpretation of the Sainte-Chapelle of Paris.
[1] Towards the end of the eleventh century, the abbey would become the home of Guibert of Nogent, who joined the monastic community there at about the age of twelve, and lived within its walls for thirty years before being elected as abbot of Nogent-sous-Coucy.
It is connected to the main church by a narrow passage, and is composed of three vaults with stained glass window-walls.
The abbey suffered greatly during the Hundred Years' War, losing its western front and six vaults.
Like all other monasteries of France, Saint-Germer-de-Fly was confiscated as State property during the French Revolution and the abbey buildings were destroyed.