Its founding as a Cistercian monastery was made possible by a gift of land by a certain Vivien, a knight and lord of La Ferté-Loupière, to Father Étienne, a secular priest, and his two companions, Théobald (Thibault) and Garnier.

The Gallia Christiana posits 1120 or 1125, while a charter from Guillaume, count of Joigny, which records a gift made by a Gérard de Chanle (Champlay) to the church of Les Écharlis, dates to 1108.

Edmond Régnier suggests a dating of 1198 rather than 1108, but without questioning either the early 12th-century foundation of the monastery at Les Écharlis or a non-Cistercian origin.

[4] An early church document – an act signed by Hugues de Toucy, archbishop of Sens, and dated 1151 – confirmed the rights of the new abbey.

A bull confirms the abbey's foundation dates from 20 November 1163 and was signed by Pope Alexander III, who had sought refuge in nearby Sens to escape from Frederick Barbarossa.

An enraged Séguin burned down the monastery, leading the monks to appeal once again to the Archbishop of Sens, now Hugues de Toucy, who sent the bishop of Auxerre to render a verdict locally.

Les Écharlis Abbey faced difficulties from the beginning, the surrounding land being barely cleared and still rather wild.

[13] Other gifts, manifest in the barns being raised around the monastery, were made by local squires at Bornisois (Villiers-sur-Tholon) and at Chailleuse (Senan).

[15] Moreover, the abbey enriched itself spiritually, especially with the growing sanctity of Saint Alpaïs, who lived as a hermit at nearby Cudot.

Miraculously cured of a skin ailment, she lived the final 30 years of her life in a total fast, eating nothing but the host every day.

This miracle attracted large crowds, while the archbishop, skeptical, put Alpaïs under constant surveillance to prove the truth of her fasting.

[17] In 1336, the papal bull Summi magistri dignatis issued by Pope Benedict XII required that Cistercian monasteries numbering more than 40 monks send at least one of them to receive theological training.

[24] The severe decrease in their numbers caused by war, the Black Death and a general decline in interest in monasticism prevented the monks from cultivating their lands themselves.

[30] During the Huguenot siege of Auxerre, the monks once again sought refuge outside the monastery and therefore were not present as the abbey house, among other structures, was destroyed.

Not only did the work of the abbey serve only to enrich a distant lord, but a single family arrogated to themselves the exclusive right to pass on the commendam.

in 1652, a squadron of 600-700 soldiers from the forces of Louis, Prince of Condé, pillaged and burned the monastery; eight villagers who had sought refuge at the abbey died in the fire despite the monks' best efforts to save them.

The church of Jean de Langeac received a new roof (though, pace Alexandre Salomon, it was not reconstructed in its entirety) and the monastic buildings, dormitory, chapter house, and refectory were completely restored.

[33] Despite everything, the monks enjoyed a good reputation and when, on 18 November 1790, two administrators from the district of Joigny came to affix the seals on the abbey, they held back.

[39] Nothing remains of the medieval monastery but the entrance to the property, which dates from the 12th century and includes a small chapel dedicated to Notre-Dame-de-Pitié.