Built in the early 19th century on the site of a former priory that had become a begging depot, it was intended to replace the outdated municipal hospice Sanitat. Originally, the role of Saint-Jacques was to provide a hospice for the insane, the impoverished elderly, and orphans.
Designed according to the most advanced knowledge available at the beginning of the 19th century, it underwent regular refurbishment to keep pace with the evolution of medical and sanitary techniques and the number of patients admitted. It then returned to its original vocation, focusing on geriatrics and psychiatry.
It probably served as a refuge for travelers on the pilgrimage to Santiago de Compostela. This priory depended on the Saint-Jouin de Marnes abbey in the Poitou region. The church built by the monks of Saint-Jacques, which serves as the priory chapel, is a blend of Romanesque and ogival styles, dating from the late 12th century.
In , Thomas James, bishop of Dol and commendatory of the monastery of Saint-Jacques, had the church restored. Between and , the abbey, now owned by the Benedictines of Saint-Maur dependent on Marmoutier Abbey , was rebuilt on the ruins of the former priory buildings. The new convent, which has no cloister, comprises a central building, the longest, parallel to the church, and two perpendicular wings at either end.
To these were added two pavilions adjoining the central part and a porch. Only four monks remained when the French Revolution broke out, most of whom took an oath and then asked to become laymen again. The priory became bien national and was sold in to a private individual, a Nantes merchant from Port-aux-vins. It was renamed Saint-Jacques de Pirmil, and separated from the rest of the property. After the Battle of Nantes on June 29, , the Pirmil neighborhood was partly destroyed, and the homeless inhabitants found refuge in the former convent.
