Michel-Joseph Maunoury (pronounced [miʃɛl ʒozɛf monuʁi]; 17 December 1847 – 28 March 1923) was a commander of the French forces in the early days of World War I who was posthumously elevated to the dignity of Marshal of France.

With a small portion of its strength rushed to the front in commandeered taxicabs, it attacked von Kluck's German First Army from the west at the Battle of the Ourcq.

[15] After meeting with Sir John French and Lanrezac (commander of Fifth Army), who were barely on speaking terms, at St Quentin on the morning of 26 August, and hearing reports (which later turned out to be exaggerated) of the destruction of British II Corps at Le Cateau, Joffre became deeply concerned about the weakness of his left flank and the risk of the British Expeditionary Force being overrun.

2, ordering a new army to be formed under Maunoury around Amiens on the French west flank, consisting of four reserve divisions and a corps.

Ebener’s Sixth Group, consisting of 61st and 62nd Infantry Divisions, both reserve formations, which had made up the Paris Garrison before being railed to Arras, were ordered to march south to block the German advance on Bapaume and Peronne (the future Somme battlefield of 1916).

Marching down from Cambrai to link up with Maunoury’s forces, they brushed aside a German cavalry screen and entered Bapaume, then on 28 August as the fog lifted they were ambushed by Linsingen’s II Corps at Moislains north of Peronne (and near Sailly-Saillisel, which was to be the scene of French operations on the Somme in 1916).

Advancing into the Santerre plain, Maunoury gave a good account of himself against von Kluck's forces at Proyart on 29 August.

The 14th Infantry Division, regulars redeployed from the east, blocked Linsingen's columns advancing along the left bank of the Somme, using concentrated rifle and artillery fire.

[25] In a handwritten note, responding to a request for information, Joffre recommended to Gallieni that “part of General Maunoury’s active forces” strike east against the German right wing.

[26][27] At 09:10 on 4 September Gallieni, following air reconnaissance reports and concerned that a continued French retreat would leave Paris uncovered and vulnerable to German attack, ordered Maunoury to be ready to strike east to take von Kluck in flank.

Joffre, who was not consulted in advance but who had separately reached the same conclusion, approved the order, while still making up his mind about the timing of Fifth Army's stand on the Marne.

Gallieni also put Antoine Drude’s newly arrived 45th Infantry Division (white settlers from Algeria) under Maunoury, raising Sixth Army to about 150,000 soldiers.

The following night (7/8 September) Kluck ordered the rest of his forces north, believing that a cavalry screen would be enough to hold back the “repeatedly beaten British”.

Police commandeered 1200 black Renault cabs and shuttled 500 of them from Les Invalides west to Gagny, where each picked up 4 or 5 soldiers then drove to Nanteuil-les-Meaux overnight.

Late on the day, sensing von Kluck's imminent counterattack, Gallieni urged Maunoury to hold his ground “with all your energy”.

[43] By the evening of 8 September, Rudolf von Lepel's brigade, marching southwest from Brussels, aimed to take Maunoury's left flank.

[45] During the fighting on the Ourcq and aware of the BEF advance from aviators’ reports, Lt-Col Hentsch of the German General Staff, concerned at the threat faced by Bulow's Second Army further south, ordered the battle broken off.

[48][49] On the evening of 9 September, with the Germans withdrawing and the BEF crossing the Marne, Joffre was not yet willing to announce victory and instead sent the War Minister a message praising Maunoury's Sixth Army for defending Paris.

[50][51] Abandoning the plan to envelop the Germans from the west, Joffre now ordered all the French armies, including Sixth, to advance northeast.

Sixth Army also launched a diversionary offensive north of Soissons and the Aisne, into solid defensive ground where the Germans had halted their retreat in September 1914, commanded by Joffre's former staff officer Henri Berthelot.

[53] Maunoury was severely wounded by being shot through the eye by a German sniper and rendered partially blind while touring the front on 11 March 1915, thereby ending his active career.