During the First Battle of the Marne, French soldiers fired their guns while using the bodies of their dead comrades as shields. This marked the beginning of trench warfare, which would come to characterize World War I.

　　　During the First Battle of the Marne, French soldiers used the bodies of their fallen comrades as shields while firing their weapons. The First Battle of the Marne, which took place from September 6 to September 10, 1914, marked the end of the German army's offensive against France and the outbreak of trench warfare, which would characterize the rest of World War I.

　　The French offensive in the Lorraine region prompted a German counterattack, pushing the French back to the fortifications. The French were able to reinforce their defenses and send troops to strengthen their left flank. Eleven divisions fighting in Belgium and East Prussia were withdrawn, further weakening the German northern flank, and the German First Army moved north toward Paris. The French were now exposed to the possibility of flank attacks and counterattacks as they attempted to cross the Marne River valley beyond the Paris defense line.

　　On September 3, the German army ordered the French to halt their retreat, and three days later, the reinforced left flank launched a general attack. The German army halted its advance to support its flanks. On September 9, the German army learned that the British Expeditionary Force (BEF) was advancing between the 2nd Army and the Crock. The German army was ordered to retreat. The counterattacks by the French 5th Army, 6th Army, and BEF developed into the First Battle of the Marne, the French army's general counterattack. By September 11, the German army had completely withdrawn.

　　The German army withdrew north of the Marne River and established a strong defensive position along the lower reaches of the Aisne River. The First Battle of the Aisne marked the beginning of trench warfare on the Western Front. The First Battle of the Marne, which forced the German army to retreat approximately 72 km and prevented the occupation of Paris, enabled the French army to continue the war. The German army occupied most of the industrial heartland in northeastern France, inflicting severe blows on the French army. The remainder of 1914 in World War I resulted in a geographical and tactical stalemate, which would require another three years and the loss of countless lives to break.