3 Reasons Why the French Attack Failed at the Battle of the Frontiers

The Battle of the Frontiers was a series of battles fought along the eastern frontier of France and in southern Belgium between 6 August and 5 September 1914. It pitted French Chief of Staff General Joseph Joffre’s Plan XVII against the  German Schlieffen plan, commanded by Helmuth von Moltke the Younger. As von Moltke noted, although both plans couldn’t succeed, they both could ‘fail in the fog of war.’

The key battles – at Mulhouse, Lorraine, the Ardennes, Charleroi and Mons – were launched more or less simultaneously.

The German Plan to wheel through Belgium and launch a massive attack on the French left flank was delayed by the advance of the French forces and the intervention of the British Expeditionary Force (BEF).

After ferocious fighting the Franco-British force was driven back into France, eventually making at stand at the Marne.

Despite determined resistance the French in particular suffered catastrophic losses. Between 6 August and 5 September they lost 329,000 casualties as well as swathes of land.

They were along with the British subsequently engaged in a long struggle to extirpate the Germans from France. 

One can put down the French failure to 3 general reasons – sub-standard equipment, inferior reservists and ill-formed tactics.



Although the German and French armies were both formidable on paper,  the French army’s size concealed some fundamental weaknesses.

German war plans worked on the principle that units should be adaptable and able to work together. Infantry were trained to accurately fire individually and concentrate their collective fire on a single target. They were also trained to work with machine gun units in defensive and offensive operations.

By contrast, the French often had no-one to liase between different units, and suffered when attacking by not co-ordinating infantry surges with suppressing artillery fire. An excess of offensive spirit exacerbated this failing.

The French ‘poilu’ uniform was totally ill-suited to modern warfare, matching red trousers with a bright blue jacket in a style unchanged since 1870. French prisoners would be openly derided by their German captors, who had uniforms designed to blend with a bleak landscape.

The French were also equipped with the Lebl rifle, an old model, and the 1886 bayonet which was 20 in long, very thin and liable to snap.

With uniforms and weaponry drawn from history, the French army was up to date in one respect – it had a fine field gun in the 75mm. However, generally the French artillery only worked well in open warfare but had too low a trajectory to trouble strong defensive installations and was doomed to lose in any counter-battery dual.



The roughly 4 million German reservists were by and large better equipped, better trained and better led than their French counterparts. The army was the embodiment of the German soul, and soldiery was a vocation of which to be proud. The Germans drew extensively from the ‘Landwehr’ and ‘Landsturm’, and these reservists were trained to the competency of regular soldiers and equipped with robust weaponry.

By contrast the French reserves were far less competent. They did not undergo the same level of training as regular soldiers and were issued sub-par weaponry.



All sides in the First World War suffered from a military culture based on the cult of the offensive and the short glorious war, but  France suffered the most. By the time the reality of industrial warfare had exposed redundant notions of classical warfare, and armies understood that modern weaponry favoured the defender, the Germans had established a foothold in France.

Before that, the idea that France’s best opportunity lay with in offence was hugely damaging. Joffre committed large armies to reckless, chaotic advances that were cut down by a stronger German force. He failed to utilise the advantage of defense against an invading German force.

Also French intelligence, which was essential to the co-ordination of offensives, proved inaccurate. It underestimated the size of the German army in Belgium and the forces opposite the 3rd and 4th French armies.

The advantage of Plan XVII lay in seizing the initiative and making rapid, substantial gains. Errors such as this jeopardised the plan’s potential.


Several factors militated against a German defeat at the Frontiers. Of all those listed, perhaps they all originate with a misguided general plan. Going on the offensive exposed the frailties and deficiencies in the French armed forces, and British reinforcements were never going to make a decisive difference to the outcome of the battles. France was committed to a suicidal, full-strength offensive with little scope for adjustment.

Alex Browne studied History at Kings College London and is an Assistant Editor at Made From History. He specializes in post-war history in the USA and Central America.

  • WW1, Great War.

    An interesting article which I enjoyed reading. So I am going to nit pick a little. A “Gun” always has a flat trajectory, it is one of the chief characteristics of a “Gun”. It is a “Howitzer” that has a curved trajectory. Victory or defeat is sometimes hard to define, a few misconceptions are in the article too. The French were perfectly aware of the “Superiority of Defence”, the French though were faced with the need to evict Germans from French territory. After the Marne the Germans were going to loose the war. It became a war of attrition and the maths will tell you the Germans were never going to win a war of attrition, but the need to evict Germans from the territory they occupied was still there. The Germans could adopt a defensive mindset, indeed they had no other worthwhile option. The British and French really had no other choice but to keep on the learning curve, keep trying, and keep adapting, until as they did in 1918 succeed in over coming the “Superiority of Defense”

    • JamesCarson

      Hi, thanks for the comment.

      Not sure why you point out guns/howitzer difference – there is no mention of howitzers in the article and French artillery at the start of the war was limited to low trajectory weapons (as Alex pointed out).

      Also I’m not convinced anyone really knew of superiority of defence from the outset – if they really were, then it beggars belief that they would continue to wear bright primary colour uniforms and attack in human waves. Also the mobilisation / war by timetable theory is completely based on the overwhelming European belief that attack was the better option.

      Really disagree with the notion that ‘after the Marne the Germans were going to lose the war’ and that it became a mathematical battle. In 1918 they nearly won it having diverted divisions from the Eastern Front.

      • WW1, Great War.

        The gun howitzer difference is the reason French counter battery fire was relatively ineffective.

        As for attacking in human waves, wars are fought with what you have, not what you desire,

        In 1918 the Germans came no where near victory. The German army was a spent force the Kaiserschlacht was doomed from the start. The Allies could, and did, trade space for time. The stormtroopers simply did not have the resources, Once out in the open the lack of supplies meant they were dead men. yes they did have limited initial success but by the time of Haig’s Backs to the Wall order the worst was over with.

        • JamesCarson

          How do you mean by the gun / howitzer difference? That the French didn’t have many? I don’t really get the ‘nitpick’ given we merely say the French artillery was ineffective. Howitzer or no.

          Not sure what you mean by the second point. Human wave attacks occurred until late in the war, often because the attackers underestimated defence vs. attack. It certainly seems that way at Frontiers (at least according to Peter Hart).

          That last point is debatable and there’ll be academics who would reason otherwise. Maybe you might want to write an article along the lines of why ‘the German army was a spent force’ in 1918.