The Hôtel-Dieu (French pronunciation: [otɛl djø]; "God Shelter") is a public hospital located on the Île de la Cité in the 4th arrondissement of Paris, on the parvis of Notre-Dame.

Run by the Catholic Church for many centuries, the hospital's original mission was to provide "Christian charity dedicated to the shelter, spiritual comfort and treatment of the ailing poor.

"[2]:44 An 18th century essayist, Louis Rondonneau de la Motte, wrote in his Essai Historique sur l'Hôtel-Dieu (1787): "the citizen and the foreigner, the Christian and the Turk, the Jew and the Idolater are all equally welcome.

By 1789, the Age of Enlightenment—with its focus on the pursuit of knowledge via reason and evidence and on ideals such as progress, fraternity, and government dedicated to the well-being of the people—had left its mark on the agenda for hospital reform.

Shortly thereafter, in 1165, Maurice de Sully, bishop of Paris, undertook the reconstruction of this hospital: the old buildings were destroyed in 1195 and the new constructions were completed in 1255.

At that time, the buildings of the Hotel Dieu occupied the south side of the Ile de la Cité near Notre Dame.

[4] In its first several hundred years, the Hôtel-Dieu functioned as a general purpose charitable institution operated by religious orders[5] — it offered food and shelter in addition to medical care to needy people.

[6] This mixed social mission characterised its services for many centuries and was imitated by many other cities (for example, the Hôtel-Dieu de Beaune, founded in 1443).

[3] From the time of Louis IX onwards, the Hôtel-Dieu often housed more patients than it was designed to hold, leading to serious problems of overcrowding that would hamper the effectiveness of the hospital for centuries.

The question of how much patients were given to eat was also an issue due to lack of funds, though people of the time understood that an appropriate diet would improve health outcomes.

The centralized approach to extreme poverty in France was based on the premise that medical care was a right for those without family or income, and formalized the admission process to attempt to mitigate overcrowding and unsanitary conditions.

Although almost 50 hospitals and similar institutions were operating in Paris by the second half of the century,[11] demand outpaced the supply of medical services, largely because of very rapid growth of both population and poverty.

[18] The Baron de Breteuil (1730-1807), acting for Louis XVI, instructed the Royal Academy of Sciences to evaluate the Poyet project.

The 1788 proposed that the pavilion-style of hospital be adopted, with each ward occupying a separate building to reduce disease transmission and to facilitate ventilation.

The third report drew heavily on information collected by Tenon and Coulomb during their official study mission to England in the summer of 1787, during which they visited 52 hospitals, prisons and workhouses.

[21] At the request of the hospital commission Tenon published his 500-page Mémoires sur les hôpitaux de Paris, which documented in detail the scandalous conditions in the Hôtel-Dieu.

The Memoires criticized virtually everything about the hospital: the space, the circulation, the arrangement of the beds, the number and the mixture of the sick, the dirtiness, the rot and the bad smells, inhumanity and mortality.

[18] Thus, Tenon's publication, combined with the work of the Academy, provided convincing scientific evidence in support of the Parisian's long standing prejudices against the Hôtel-Dieu.

[14] Jacques Necker created the positions of Inspecteur général des hôpitaux civils et des maisons de force (General Inspector for civil hospitals and jails) and Commissaire du roi pour tout ce qui a trait aux hôpitaux (Royal Commissioner for all that relates to hospitals).

The use of hospitals as teaching institutions was also reinforced as part of the reform movement, which studied medical practice and policy in other European countries.

[12] The Hôtel-Dieu achieved renown as a surgical training institution with the appointment of Pierre-Joseph Desault as chef de service in 1785.

Oriented towards informing the patient (therapeutic education) and technological innovation, it offers a large choice of care facilities for all levels of complications.

It is also at the forefront of diabetes research in such areas as new insulins and drugs, the effects of nutrition, external and implanted pumps, glucose sensors and artificial pancreas.

[26] Other notable physicians, researchers, and surgeons who practised at the hospital include Jean Méry, Forlenze, Bichat, Dupuytren, Adrien Proust, Hartmann, Desault, Récamier, Cholmen, Dieulafoy, Trousseau, Ambroise Paré, Marc Tiffeneau, Augustin Gilbert.