He attended the École polytechnique and was commissioned into the engineers. A fellow student at the École was Joseph Joffre, and Roques' career was influenced by their continuing ties.
Roques served in Algeria in 1880, the first in a series of colonial assignments that stretched for twenty-five years. He volunteered for duty in Tonkin in 1885 and commanded a battalion in Dahomey, where he was wounded, in the 1890s. In the rank of colonel he directed railroad construction in Madagascar, 1897-1905, under General Gallieni. Joffre was a comrade in arms for Roques both in Tonkin and Madagascar. Colonel Roques became General Roques in 1906 and advanced to major general four years later. He played an important role in promoting French air power as inspector of military aviation, 1910-1912.
Roques proved himself to be an undistinguished combat leader in the large-scale encounters of 1914. He led a corps into Belgium under Langle de Cary, then fought under Foch at the battle of the Marne. Neither his performance in the Fourth Army nor in Foch's Ninth was marked by skill or initiative. Nonetheless, Joffre promoted him to command the First Army in early 1915. For over a year Roques fought on the relatively quiet front of the Eastern Army Group under General Dubail. Much of Dubail's time and energy was spent in stimulating Roques' lackadaisical leadership.
In March 1916, Roques suddenly rose to become minister of war. Once again, Joffre's hand smoothed the way. With the departure of Gallieni from the War Ministry, the commander in chief needed a reliable and unambitious figure to stand between the High Command and interference from the government. The affable Roques turned out to be an unpleasant surprise. He rejected the role of "a sub-Joffre, criticized the defense of Verdun, and demanded that the upper ranks of the army be purged. One casualty inflicted by the war minister was an outraged General Dubail. In August 1916, Roques clashed with Joffre on the perennial issue of opening the front to parliamentary inspection.
Roques proved equally uncomfortable a subordinate for Premier Briand . Dispatched to Salonika in October, Roques was expected to return with a report critical of General Sarrail, the French commander in the Balkans. Briand intended to use this document as his excuse to order Sarrail home. Instead, Roques praised Sarrail, suggesting he be reinforced as well as freed from Joffre's supervision. Evidence indicates that Sarrail's parliamentary supporters knew the substance of the Roques report before the war minister left France for the eastern Mediterranean. This link between the war minister and the parliamentary Left gravely embarrassed and weakened Briand. Barely surviving a rebellion in the Chamber of Deputies, he rid himself of the unpredictable Roques in December. In all, Roques' nine months as war minister were marked by the declining prestige of the military High Command and the ascending influence on military policy of a restive National Assembly. In Joffre's memoirs the angry commander in chief cast these events in a different light, recalling his fear of Roques' "lack of character vis-à-vis the parliamentarians."
Roques returned to the command of a field army in 1917, then served as inspector of defensive fortifications on the western front during the last year of the war. He died in Saint-Cloud, February 26, 1920.