Founding
The current institution finds its roots in the creation of the Ecole normale de l'an III by the post-revolutionary National Convention led by Robespierre in 1794. The school was created based on a recommendation by Joseph Lakanal and Dominique-Joseph Garat, who were part of the commission on public education. The Ecole normale was intended as the core of a planned centralised national education system. The project was also conceived as a way to reestablish trust between the Republic and the country's elites, which had been alienated to some degree by the Reign of Terror. The decree establishing the school, issued on 9 brumaire, states in its first article that "There will be established in Paris an Ecole normale (literally, a normal school), where, from all the parts of the Republic, citizens already educated in the useful sciences shall be called upon to learn, from the best professors in all the disciplines, the art of teaching."
The inaugural course was given on 20 January 1795 and the last on 19 May of the same year at the Museum of Natural History. The goal of these courses was to train a body of teachers for all the secondary schools in the country and thereby to ensure a homogenous education for all. These courses covered all the existing sciences and humanities and were given by scholars such as: scientists Monge, Vandermonde, Daubenton, Berthollet and philosophers Bernardin de Saint-Pierre and Volney were some of the teachers. The school was closed as a result of the arrival of the Consulate but this Ecole normale was to serve as a basis when the school was founded for the second time by Napoleon I in 1808.
On 17 March 1808, Napoleon created by decree a pensionnat normal within the imperial University of France charged with "training in the art of teaching the sciences and the humanities". The establishment was opened in 1810, its strict code including a mandatory uniform. By then a sister establishment had been created by Napoleon in Pisa under the name of Scuola normale superiore, which continues to exist today and still has close ties to the Paris school. Up to 1818, the students are handpicked by the academy inspectors based on their results in the secondary school. However, the "pensionnat" created by Napoleon came to be perceived under the Restoration as a nexus of liberal thought and was suppressed by then-minister of public instruction Denis-Luc Frayssinous in 1824.
Second founding
An École préparatoire was created on 9 March 1826 at the site of collège Louis-le-Grand. This date can be taken as the definitive date of creation of the current school. After the July Revolution, the school regained its original name of École normale and in 1845 was renamed École normale supérieure. During the 1830s, under the direction of philosopher Victor Cousin, the school enhanced its status as an institution to prepare the agrégation by expanding the duration of study to three years, and was divided into its present-day "Sciences" and "Letters" divisions. In 1847 the school moved into its current quarters at the rue d'Ulm, next to the Panthéon in the 5th arrondissement of Paris. This helped it gain some stability, which was further established under the direction of Louis Pasteur.
Having been recognised as a success, a second school was created on its model at Sèvres for girls in 1881, followed by other schools at Fontenay, Saint-Cloud (both of which later moved to Lyon, and Cachan). The school's status evolved further at the beginning of the twentieth century.
In 1903 it was integrated into the University of Paris as a separate college, perhaps as a result of its exposition to national attention during the Dreyfus Affair, in which its librarian Lucien Herr and his disciples, who included the socialist politician Jean Jaurès and the writers Charles Péguy and Romain Rolland spearheaded the campaign to overturn the wrongful conviction pronounced against Captain Alfred Dreyfus. The ranks of the school were significantly reduced during the First World War, but the 1920s marked a degree of expansion of the school, which had among its students at this time such figures as Raymond Aron, Jean-Paul Sartre, Vladimir Jankélévitch and Maurice Merleau-Ponty.
Twentieth century
After the Second World War, in which some of its students were players in the Resistance, the school became more visible and increasingly perceived as a bastion of the communist left. Many of its students belonged to the French Communist Party. This leftist tradition continued into the 1960s and 1970s during which an important fraction of French maoists came from ENS. In 1953 it was made autonomous from the University of Paris, but it was perceived ambivalently by the authorities as a nexus of protest, particularly due to the teachings delivered there by such controversial figures as political philosopher Louis Althusser. As of now, by law, ENS comes under the direct authority of the Minister for Higher Education and Research.
The fallout from the May 1968 protests caused President of the Republic Georges Pompidou, himself a former student at the school, to require the resignation of its director, Robert Flacelière and to appoint his contemporary Jean Bousquet as his successor. Both Flacelière and Bousquet were distinguished classicists.
The school continued to expand and include new subjects, seeking to cover all the disciplines of natural and social sciences. In this manner, a new concours was opened in the 1982 to reinforce the teaching of social sciences at the school. The concours, called B/L (the A/L concours standing for the traditional letters and human sciences), greatly emphasises proficiency in mathematics and economics alongside training in philosophy and literature.
For a long time, most women were taught at a separate ENS, the École normale supérieure de jeunes filles at Sèvres. However, women were not explicitly barred entry until a law of 1940, and some women were students at Ulm before this date, such as philosopher Simone Weil and classicist Jacqueline de Romilly. In 1985, after heated debates, the two were merged into a single entity with its main campus at the historic site at the rue d'Ulm in Paris.