A few years later, the Brothers had to move because, Marguerite de Valois, the first wife of Henri IV, had decided in 1607 to establish a convent there (future convent of the Petits-Augustins, established within the perimeter of the current National School of Fine Arts or Beaux-Arts de Paris).

It opened under the name of Saint Jean Baptiste de la Charité and was available only to male patients who did not suffer from incurable or venereal diseases.

From 1613 onwards, the Brothers engaged in a major construction project, which created several important hospital structures.

[4] The chapel still stands at the corner of the boulevard Saint-Germain and the rue des Saints-Pères.From 1652,[3][5][6] the Brothers of Charity also acquired – thanks to an anonymous donation – a house on rue du Bac, which was initially equipped with eight beds for poor convalescents after their discharge from hospital.

Two monks and a servant (who were fed and housed according to the terms of a contract established on March 30, 1652) watched over the convalescents during their stay.

[11] In the late 18th-century, the hospital innovated in the delivery of clinical education; Louis Desbois de Rochefort (1750-1786) initiated bedside instruction for medical students that focused on the patients' symptoms and physical signs as diagnostic indicators, marking a major development in the history of medicine in France.

Rochefort was succeeded by his assistant Jean-Nicolas Corvisart in 1788, who questioned the traditional humoral theory, and employed more physical methods of diagnosis such as palpitation and percussion.

[9] The Brothers of Charity were forced by the Revolutionary government to abandon the hospital in 1791 (though they continued to provide medical services there until their final departure in 1801) due to the confiscation of properties of the Catholic Church.