In later life, Barrès returned to the Catholic faith: he was involved in a campaign to restore French church buildings and helped establish 24 June as a national day of remembrance for St. Joan of Arc.

Born at Charmes, Vosges, he received his secondary education at the lycée of Nancy, attending there the lessons of Auguste Burdeau, later pictured as social climber Paul Bouteiller in Les Déracinés.

A year after establishing himself in Neuilly, he began his trilogy in 1897, Le Roman de l'énergie nationale (Novel of the National Energy), with the publication of Les Déracinés.

[3] Affected by the Dreyfus Affair, and finding himself on the side of the Anti-Dreyfusards, Barrès played a leading role alongside Charles Maurras, which initiated his shift to the political right; Barrès oriented himself towards a lyrical form of nationalism, founded on the cult of the earth and the dead ("la terre et les morts", "earth and the dead" — see below for details).

[3] The Roman de l'énergie nationale trilogy makes a plea for local patriotism, militarism, the faith to one's roots and to one's family, and for the preservation of the distinctive qualities of the old French provinces.

Six of them survive in the second novel of the trilogy, L'Appel au soldat (1900), which gives the history of Boulangism; the sequel, Leurs figures (1902), deals with the Panama scandals.

But he returned in his later years to the Catholic faith, engaging in L'Echo de Paris a campaign in favour of the restoration of the churches of France.

As a young man, Barrès carried his Romantic and individualist theory of the Ego into politics as an ardent partisan of General Boulanger, locating himself in the more populist side of the heterogenous Boulangist coalition.

[7] He founded the short-lived review La Cocarde (The Cockade) in 1894 (September 1894 – March 1895[8]) to defend his ideas, attempting to bridge the gap between the far-left and the far-right.

In 1908, he opposed in Parliament his friend and political opponent Jean Jaurès, refusing the Socialist leader's will to Pantheonize the writer Émile Zola.

During the war Barrès also partly came back on the mistakes of his youth, by paying tribute to French Jews in Les familles spirituelles de la France, where he placed them as one of the four elements of the "national genius", alongside Traditionalists, Protestants and Socialists – thus opposing himself to Maurras who saw in them the "four confederate states" of "Anti-France".

[5] Opposed to Jean-Jacques Rousseau's theory of social contract, Barrès considered the 'Nation' (which he used to replace the 'People') as already historically founded: it did not need a "general will" to establish itself, thus also contrasting with Ernest Renan's definition of the Nation.

[13] Influenced by Edmund Burke, Frédéric Le Play and Hippolyte Taine, he developed an organicist conception of the Nation which contrasted with the universalism of the 1789 Declaration of the Rights of Man and of the Citizen.

[13] According to Barrès, the People is not founded by an act of autonomy, but find its origins in the earth (le sol), history (institutions, life and material conditions) and traditions and inheritance ("the dead").

[13] Contrary to popular belief, Maurice Barrès never used the term “le grand remplacement” [great replacement], either in his novel "L'appel au soldat" or anywhere else.

[17] Influenced by the romantic mythification of Spain, he described the country as "an Africa leaving your soul with a sort of furor so fast as chilli does in your mouth".

[20] The Dadaists organised in spring 1921 the trial of Barrès, charged with an "attack on the safety of the mind" ("attentat à la sûreté de l'esprit") and sentenced him to 20 years of forced labour.