In early September, the French army, which had no way to retreat, was determined to launch a counterattack on the Marne line and make it a strategic battle to turn the situation around. Xia Fei deployed the main force of the French army east of Paris, laying it in a pocket shape

He shouted scared the British commander to tears, and finally agreed to send troops to aid Battle of the Marne River

In early September, the French army, who had no way out, was determined to launch a counterattack on the front line of the Marne River and make it a strategic battle to turn the situation around. Xia Fei deployed the main force of the French army east of Paris, laying it in a pocket shape to the east, and retreating in the middle with both wings protruding to attract the German army to attack. The battle first started on Olque's main battlefield. At noon on September 5, under the command of General Crook, the 1st German Army was advancing southward through Paris, attempting to encircle the entire French army from the left wing. The German army, who was blinded by victory, judged that the French army had already been defeated at this time.

Therefore, when they looked at the figure of the Eiffel Tower in Paris, they couldn't help but cheer. But at this moment, the right wing of the German army was suddenly attacked by the vanguard of the French army's 6th Army. General Crook immediately ordered the two armies on his right wing to launch a counterattack. The 6th French Army Corps was originally a temporary unit formed to defend the capital Paris. The corps is commanded by General Monuri, who has long been retired, and has 150,000 subordinates. However, due to the hasty formation, some troops are still on the way. Monuli, under the strong pressure of the German offensive, hurriedly ordered the legion's follow-up troops to provide rapid reinforcements. At this time, the 7th Division, which was assigned to the legion, had already gotten off the train near Paris, but was unable to arrive quickly because there was no railway line to the front line.

Therefore, the need for war inspired General Gallieni and formed the first motorized force in the history of world wars. He issued an order to requisition Paris city "all motor vehicles including taxis". Paris police were ordered to intercept and requisition more than 700 taxis on the streets. That night, 700 cars ran back and forth only two times before sending all the 7th Division to the front line. General Monuri finally stabilized his front line and opened the prelude to the Battle of the Marne with this action. After the battle began, Xia Fei was deeply dissatisfied with the British army's constant stagnation. After several electric urges failed, on the morning of September 5, he personally took a bus to Milun, 100 miles away, and urged Marshal French, the commander-in-chief of the British Expeditionary Force, in person.

During the talks, Xia Fei changed his taciturn habit and shouted passionately: "The lives of all the people of France, all the territory of France and the future of Europe are all here... I cannot believe that at this time of danger, the British Army will refuse to take its responsibility... History will make a harsh judgment on your absence!" Seeing that the British commander was still hesitating, Xia Fei punched the table and shouted: "Mr. Marshal, the honor of Britain has been threatened!" French couldn't help but blushed, and two lines of tears rolled down his cheek. He wanted to answer in French, but felt that he was not satisfied, so he said to his deputy chief of staff: "It's terrible, I can't explain it clearly. Tell him that we will do everything we can to assist the French army."

At dusk that day, Xia Fei had already rushed back to his front command. After entering the war room, he said to the officers gathered there: "Everyone, we will fight a war on the Marne River." Then he gave a simple, clear but unwavering mobilization order: When the national security is in this battle, all personnel must realize that the retreat phase has ended. At present, we should do our best to launch an attack and drive the enemy back. Even if any unit finds that its troops are no longer able to advance, it must sacrifice its place to defend and never take a step back. Under the current circumstances, no failure can be allowed. Since September 6, under Xia Fei's strict supervision, the French army launched a full-scale counterattack.

On September 8, the 6th Legion fought fiercely with the German army, but only one mile was made in one day. It happened that East Prussia in Germany was frequently attacked by Russian troops, so the 3rd and 9th armies of the German army were transferred from the front line by its headquarters on that day. The French army took the opportunity to advance that night and soon captured Marqins, leaving Montemirne nearby in an undefensive state. In this way, the French army nailed a wedge between the German First Legion and the 2nd Legion and the French advanced to seize the victory.The 6th Army forced the 1st German Army to gather on the Olque River, while Espery's troops forced the 2nd German Army to retreat northeastward.

On September 9, at the critical moment of the battle, a British army led by France also quietly entered the gap between Crook and Biro. The timely joining of British troops strengthened the French army's wedge-shaped offensive, thus making it impossible for the German 1st and 2nd legions to meet again. People call this tactical operation "the miracle of the Marne River" and believe it was this operation that saved the entire situation in France. Xia Fei, who had been looking forward to British reinforcements, was ecstatic after hearing the news. He quickly ordered Monuli and Espery to hold on to the Germans in front of them. As a result, the gap became wider and wider, making the British army's second and third troops enter a no-man's land. Within three days, the British army stood at the gap between the 1st and 2nd German legions, thus completely separating the head and body of the German army.

Xiafei ordered the British army to continue advancing, cross the Marne River, and directly attack Crook's left wing and behind, and at the same time ordered the French 5th Legion to cover the British army's right wing. During the Battle of Marne River, the German Supreme Commander 2 ordered the 6th Legion, which was fighting against the French army in the east, to quickly draw troops to help the west. However, the two French turrets, Tur and Erbinar, ruthlessly bombarded the German reinforcements with fierce artillery fire with fierce artillery fire. On September 8, Prince Ruprecht, commander of the 6th German Army Corps, was forced to notify the Supreme Command that most of the reinforcements he sent had been killed or injured and could no longer advance. At the same time, the situation in the German army in other directions was also not good.

In the northeast of Verdun , the 5th German Army, which was fighting fiercely with the French 3rd Legion, was also seriously injured by the unstoppable artillery fire of Verdun's forcing his commander, Prince William, ordered the cessation of advancement. The 4th Legion commanded by the Duke of Wittenberg in Germany and the 3rd Legion commanded by General Max von Hausen were hit by the troops of General Delanger de Cali and General Ferdinand Foch in the Sãognar swamp. The entire Battle of Marne was carried out along the 200-mile frontline, with countless fierce, short, chaotic conflicts and battles.

Since the beginning of the war, the German army has not concentrated its absolute superior forces on the right wing according to the " Schliffen Plan ", resulting in the German army not forming a military advantage in the Battle of the Marne River. After the war broke out, Moltke shortened the German invasion front that rotated with Metz as the pivot due to other obstacles and delays, and did not surround Paris from the west. A few weeks later, when the Germans attempted to capture Paris with a frontal assault, it was too late. On September 12, in order to escape the fate of being completely defeated in the Marne region, the German army took the initiative to retreat 55 miles from the region, retreated into the mountainous Sand River region in northeastern France, and prepared to spend the winter here. The Battle of Marne ended with a crushing defeat of the German army.