[1] It served as the wartime equivalent of the Conseil supérieur de la guerre and had extensive powers within an area defined by the French parliament.

The GQG was activated by parliament on 2 August 1914, after the violation of French borders by German military patrols, and remained in existence until 20 October 1919.

GQG was commanded by the chief of staff, assisted by a varying number of subordinate generals, and had representatives to the French government and president.

The headquarters of GQG was originally at Vitry-le-François in the Marne department but rapid German advances in the early stages of the war forced its withdrawal to Chantilly, near Paris, by November 1914.

Nivelle in turn was replaced in May 1917, after the failure of his spring offensive, by General Philippe Pétain, who retained command of GQG until its dissolution in 1919.

In April 1918 the Grand Quartier Général des Armées Alliées [fr] (GQGA) was established under General Ferdinand Foch as an equivalent organisation with authority for Allied operations in France.

GQG, under Joffre, assumed control of these armies in December 1915 and retained them until his replacement by Nivelle when the Minister of War, Joseph Gallieni, raised concerns that the pre-war policy was being violated.

Though these officers were junior in rank to the generals commanding the armies, they held significant power over their careers through the reports made on their operations to GQG.

[7][12][13] The other officers were generally selected by Joffre from those who had excelled at the Ecole Supérieure de Guerre (French Army staff college).

[5] The officers in that department, particularly the recent staff college graduates who were known as the Young Turks, favoured strong offensive action.

The GQG officers, isolated from the direct effects of the war, engaged in intrigue on a grand scale and there was little co-operation between the rival departments.

Thus the Third Bureau found itself directing French generals to undertake military operations based on wholly inaccurate assessments of the strength of opposing units.

[12] French set-backs in 1915 forced Joffre to reorganise GQG—on 11 December he replaced Belin with General Noël de Castelnau—and expand its remit.

[6] Despite this reorganisation GQG remained dysfunctional with the Second Bureau, described as "perennial optimists" by Horne, again responsible for providing deceptive assessments of German casualties, at one point in the Battle of Verdun simply adding "a hundred thousand or thereabouts" every fortnight to the figures.

[18] The Third Bureau was responsible for withdrawing two and a half batteries of artillery from the fortresses of Verdun in the months leading up to that close-fought battle, despite receiving requests for reinforcements from the local commander General Frédéric-Georges Herr, who stated he could not hold if attacked in force.

This course of action was justified by the Ministry of War as an essential step in restoring the independence of the two armies, a key pre-war policy that had been established in a ministerial decree on 28 October 1913.

Pétain expanded GQG's operations, establishing a new Section for Relations with the Civil Authorities and a Bureau for Aeronautics, Telegraphy and Aviation.

After the armistice GQG moved to Metz in the newly reacquired Moselle department on 1 December 1918 and returned to Chantilly on 29 January 1919.

[22] After April 1918 all Allied troops on the Western Front were placed under the command of the Grand Quartier Général des Armées Alliées [fr] (GQGA), a multi-national general staff that developed from the Supreme War Council.