Augustin Dubail graduated from the military school of Saint-Cyr in 1870 and was commissioned an officer in the infantry. During the Franco-Prussian War Dubail fought at Saarbrücken, Spicheren, Borny before being captured at Metz.
A graduate of the War College in 1878, Dubail held a series of choice staff and line posts that indicated he had been singled out for high responsibilities in the future. An aide to the minister of war from 1883 to 1887, then an instructor at St. Cyr, Dubail advanced rapidly to a colonel's rank and command of a regiment by 1901. Three years later he was a major general. He commanded at St. Cyr (1905-1908), led the Fourteenth Division at Belfort for three years until, in 1911, he was chosen to be the army's new chief of staff. Dubail's rapid rise owed much to his acknowledged energy and military skill; but it did not hurt him to be identified as a loyal republican in a largely conservative officer corps.
The Agadir crisis of 1911 dominated the months after Dubail took his new position. He played a major role in solidifying France's military ties with its future wartime allies. After his discussions with the British in July, the size, shipment schedule, and continental zone of concentration for the British Expeditionary Force were specified. In August Dubail's mission to Russia led to a specific Russian timetable for an offensive against Germany in the event France faced attack from its hostile neighbor to the east. In 1912 Dubail took over the IX Corps at Tours and became a member of the Supreme War Council. His post of chief of staff had been largely superceded by the new position of chief of the General Staff given to General Joffre.
In August 1914, Dubail led the First Army in its offensive toward Sarrebourg. He fell back on August 20 in the face of the German counteroffensive in Alsace-Lorraine. In contrast to General de Castelnau's leadership of the Second Army on his left, Dubail retreated reluctantly and in good order, taking up a defensive position behind the Meurthe River. There he held the eastern anchor of the French line during the battle of the Marne in early September, meanwhile sending much of his fighting strength by rail to reinforce the armies near Paris. By the close of the year, Dubail commanded the largest sector on the western front, stretching from Belfort to Verdun. Joffre drew freely on this relatively silent sector for reinforcements. Meanwhile Dubail, a general out of Joffre's own mold, conducted vigorous local attacks and counterattacks. In January 1915, Dubail formally took command of the Eastern Army Group, a role he had in fact held since September 1914.
Dubail never implemented his plans for large-scale offensive operations on his sector in 1915. Joffre continually drew both men and ammunition from the Eastern Army Group for the spring offensive in Artois and subsequent operations in Champagne. Dubail continued with local attacks and sometimes found himself the target of similar thrusts by the enemy. In July one of these German advances struck the French Third Army commanded by General Sarrail in the Argonne. Joffre named Dubail to investigate the affair, in which the French had been surprised and then suffered heavy losses. The commander in chief strongly intimated that he expected Dubail to recommend that Sarrail be severely punished. Joffre clearly hoped Dubail's reputation as a republican would shield the High Command from charges of taking political reprisals against the equally republican Sarrail. Dubail tried to placate both sides in the dispute. His report characterized Sarrail as a good officer with some poor qualities, and he recommended that Sarrail be transferred, not cashiered. Joffre responded by firing Sarrail, who was rescued in turn by his circle of political allies.
During 1915 Dubail strongly advanced the idea that Russian troops be brought in to fight on French territory. His own role as supplier of manpower to more active fronts convinced him that only such drastic measures could fill the gaps incurred by France's growing battle losses. By early 1916 the first Russian brigade was on its way.
Dubail's reputation was broken by the Verdun debacle. As early as July 1915, he had officially described the Verdun defenses as adequate when questioned by members of the National Assembly. The following month, his instructions to the Verdun commander specified that no siege was expected and none could be permitted. Verdun, he said, must be defended by the use of mobile forces. Like Joffre and the commander in chief's staff, Dubail considered such fortresses to be outdated. But even Dubail grew alarmed during the fall of 1915 when Joffre stripped Verdun of both artillery and machine guns to support offensives to the west. As artillery duels and German transport activity sounded louder and louder in November/December, Dubail warned Joffre with increasing urgency.
In mid-January, Dubail protested the commander in chief's plan to shift Verdun from the Eastern to the Central Army Group. An attack was imminent and the change, logical on paper, was completely ill-timed. Joffre rejected the advice.
Dubail played his usual subsidiary role in the aftermath of the German attack. His front yielded the first reserves for Verdun while the Eastern Group commander himself languished in enforced idleness. In late March, Joffre fired Dubail, making him the highest ranking member of the circle of generals ousted following the attack on Verdun. Dubail was not shunted aside completely; he received the post of military governor of Paris, which he held for the remainder of the war. He took the rear area job with bitterness, seeing himself as a scapegoat for Joffre, whom the politicians could not yet find the courage to oust. Moreover, the purge was conducted by General Roques, Joffre's hand-picked candidate for war minister. (Roques had served with a conspicuous lack of distinction as one of Dubail's army commanders since early 1915.)
Dubail was active as an official of the Legion of Honor after the war. He died in Paris on January 7, 1934.