The _fréres de Saint-Yon_, having been invited, in 1705, to come and establish themselves in Rouen, by the archbishop Nicolas Colbert and the first president Nicolas Camus de Pont-Carré, they accordingly purchased the portion of ground, which bears their name, in 1708. They erected the church themselves without the assistance of an architect, even acting as masons and workmen. The first stone was laid on the 7th june 1728. This edifice is of remarkable execution. In the exterior, its elevation is about ninety six feet including a lantern of about thirty, which stands above the transept of the edifice. In the interior, the length is one hundred and twenty five feet and the breadth twenty five feet. On the 16th of july 1734, the _Frères de Saint-Yon_, carried with great pomp, to their Church, the remains of their founder, the venerable Lasalle, who died in 1719, and was buried in the church of Saint-Sever. Independently of poor children, who were instructed by the monks according to their condition, they likewise received incorrigible children, who were sent by their parents to be taken care of; they also received a limited number of insane persons, thirty were habitually kept here at the expence of their families. From the time when the _Frères de Saint-Yon_, as also all other religious communities, were suppressed, untill 1820, the house of Saint-Yon, became successivly a revolutionary prison, a barrack, a _grenier d'abondance_, or corn store house, a house of detention for spanish prisoners, an hospital for wounded soldiers in 1814, and a poor house. This last establishment was one of the most considerable of this description; but, it was suppressed in 1820, by royal ordonance. Already in the preceding year, the _Conseil général_ of the departement of the Seine-Inferieure had taken into consideration the deplorable state, to which the unfortunate insane were reduced, and they resolved to alleviate their wretched condition. It had been represented to them that these unfortunate people could not receive in the hospitals of Rouen, Havre or Dieppe, where there were great numbers of them shut up, the great attention, which their position required, or not even those which humanity demanded. The _conseil général_ on a proposition from Mr Malouet, then prefect of the departement, voted the establishment of a special asylum for the insane belonging to the departement. The buildings and dependencies of the ancient monastery of Saint-Yon were designated as being fit for that purpose. The situation of the place at the extremity of the suburb, and in a healthy situation, and the numerous plantations which it would be easy to make in the large gardens which surround the establishment, appeared as many favourable circumstances, to fix the choice of the administration. Therefore, in 1821, they entered into a contract for the building of five different courts for the treatement of insane persons.