The Schlieffen Plan is the name given to Germany's tactics in the opening stages of the Great War. These tactics sought to defeat the French quickly on the Western Front before the Russian army on the Eastern Front had a chance to mobilise, and were inspired by a military plan devised by Alfred von Schlieffen. The extent to which von Schlieffen's original plan was implemented and whether or not the original plan could have succeeded have been subject to debate and disagreement by historians over the last hundred years.

Who was Alfred von Schlieffen?

Alfred von Schlieffen (1833-1913) was the successor to Helmuth von Moltke the Elder, the general who had defeated France in the Franco-Prussian War. Alfred von Schlieffen was appointed Chief of the General Staff in 1891, a position he held until 1906. It was in 1905-6 that he developed his final version of the German army tactical deployment guide known as the Schlieffen Plan.

It is said that the plan was so important to von Schlieffen that his dying words concerned it: It must come to a fight, but do not weaken the right flank. Von Schlieffen died in January 1913, just before his 80th birthday.

Germany and the Development of the Plan

Since the 1880s, relations between Germany and Russia grew extremely hostile, with the possibility of conflict increasingly likely. France too was strongly anti-German, having lost the Franco-Prussian War (1870-1). In 1893 Russia entered into a defensive pact with France called the Dual Alliance treaty. This stated that if either country was attacked, the other would come to its aid.

This gave Germany a large potential problem; if war came, Germany would face a war on two fronts. How could it win if its army was divided? Especially as both France and Belgium were constructing fortresses aimed to prevent any invasion. If Germany was fenced in, defeat would be inevitable. Yet the Schlieffen Plan was devised as a method in which to solve these problems and ensure victory for Germany over both Russia and France should a war occur.

The Plan's Principles

The first principle put into place was that in order to win, Germany would need the element of surprise. Which country, then, should be attacked first, Russia or France?

Russia was nicknamed 'the Steamroller'. It was believed that their army would be slow to fully mobilise, but because of its vast numbers, was immensely powerful and difficult to slow down or stop. Von Schlieffen estimated that it would take at least two months for Russia to mobilise.

Von Schlieffen knew that France would not take so long to prepare. France was a much smaller military power than Russia that Germany had defeated in the Franco-Prussian War. Von Schlieffen decided then that when Germany declared war on Russia, the German Army would first march west and conquer France, before turning east and conquering Russia.

With the basic premise decided, precision planning and timing would be needed in order to conquer France in just eight weeks. The problem was that France's border with Germany was extensively fortified and would be heavily defended. Von Schlieffen thought that the heavy French fortification would make it impossible to defeat France quickly by attacking head on across the Franco-German border with the number of soldiers available. The only way to attack France swiftly would be to bypass the French fort system, which meant either heading north or south of the border through a neutral country. Switzerland was obviously too mountainous, yet despite the presence of its forts, Belgium was a far more practical proposition.

Von Schlieffen decided that he should leave a portion of the German army in the east to defend from any preliminary Russian foray, while leaving some soldiers on the Franco-German border at Alsace-Lorraine, where he predicted that the French army would attack. Alsace-Lorraine was German-held territory that had been conquered from France following the Franco-Prussian War that France would seek to recapture. Rather than confront the main French army head on, he planned to advance the majority of his army through Belgium, north of Germany's border with France, while drawing the French army into a trap at Alsace-Lorraine. With the French army distracted some distance away, the main German force would manoeuvre west of Paris, capture the capital city, wheel back to attack the French army at Alsace-Lorraine from behind and complete the trap, thus defeating France.

Belgium, Man, Belgium!

Out-manoeuvring the French army in this way by attacking Belgium did have potential problems. The prospect of moving the vast German army, as well as their ammunition, fuel, food and other supplies was bordering on an impossible logistical exercise to say the least. Belgium had a small, vulnerable railway system that not only was not intended for such a task but also would need to be captured swiftly, without the loss of too many key bridges. To complicate matters further, the heavily fortified Belgian city of Liège, widely believed to be impregnable, stood directly in their path. This meant that vital time would be spent capturing Liège, while everything else was swiftly moved through Belgium rapidly enough to take Paris and then defeat the French army, ready to take on Russia.

Britain's Old Contemptibles

Another drawback of this strategy was that it risked involving Great Britain in the war. Though traditionally Britain had a comparatively small army, the Royal Navy was intended to be more powerful than any other two navies in the world combined and could enforce a blockade. The Treaty of London, 1839, stated that Britain would aid Belgium against foreign attack. However, considering Britain's tiny army had been reliant on part-time volunteers such as the Yeomanry and Militia in case of attack and the Second Boer War (1899-1902) exposed the British army's shortcomings, von Schlieffen was not particularly worried. If France and Russia were defeated quickly and according to plan, the war would have ended before a naval blockade would have had any effect.

Yet von Schlieffen had conceived his plan in stages by 1906. By the time it was enacted, Britain had also joined the alliance against Germany, signing the entente cordiale with France in 1904 and Anglo-Russian entente in 1907. Britain had learned the lessons of the Boer War too and had completely remodelled its army. Despite the Liberal government's reluctance regarding military spending and reduced military budget, Secretary of State for War Richard Burdon Haldane created an extremely well-equipped and very highly trained British Expeditionary Force. The British army's new philosophy was founded on accurate, rapid rifle fire, with the standard Lee-Enfield rifle¹ holding a detachable 10-round magazine when the German Mauser rifle held only five rounds. British soldiers were trained to be able to fire at least 15 rounds a minute with 80% accuracy. It was also ensured that ammunition was interchangeable with the army's machine guns. Though consisting of only 100,000 men and dismissed by Kaiser Wilhelm as a contemptible little army (a comment that led to the troops labelling themselves 'the Old Contemptibles'), the small, overlooked army would prove pivotal to the plan's failure.

The Plan in Action

War was declared the year after von Schlieffen had died, and his successor, General Helmuth von Moltke the Younger, changed key parts of the plan. Von Schlieffen had conceived of five vast German armies marching through France, leaving the German border only lightly defended. He also planned to ignore potential distractions in Belgium and on the eastern border until France was defeated. Von Moltke, however, feared this could lead to catastrophe and deployed far fewer men to the invading force, keeping more in reserve for defence.

On 2 August, 1914, Germany invaded Belgium as part of von Moltke's modified version of the plan. This action led to Britain declaring war on Germany on 4 August. The German First Army, commanded by General Alexander von Kluck, led the northernmost right-flank, supported closely by Field Marshal Karl von Bülow leading the Second Army. The impregnable fortress of Liège was attacked, but resisted the German offensive for five days longer than von Schlieffen predicted. It was not until Germany was able to deploy their infamous 'Big Bertha' siege howitzers that Liège fell, after being bombarded by the German superweapons for just a day. Belgium was open to German troops by 13 August.

Where There's a Rail There's a Way

Germany had engaged in major railway building in preparation for war, as the Franco-Prussian War had taught them the vital importance of being able to move troops quickly. Quadruple-track railways were built across Germany to allow troops to travel across the country, with stations designed for the swift movement of troops. When war was declared, a phenomenal timetable ensured that trains crossed the Rhine bridges at two or three minute intervals, both day and night.

Here Comes Alsace-Lorraine Again

Despite the German advance in the north, the French army under General Joseph Joffre enacted their Plan XVII on 14 August. This was the predicted mass-invasion of Alsace-Lorraine, heading right into the German trap on schedule. Yet von Moltke had chosen to weaken his attacking force in order to strengthen the defence at Alsace-Lorraine.

One often overlooked factor in the early stages of the war was how swiftly the British Expeditionary Force under General John French was assembled and positioned in France following the invasion of Belgium, a logistical triumph orchestrated by the former Secretary of State for War Jack Seely. While France reluctantly accepted Britain as an ally, they wanted to keep the British army out of the way of where they felt the key battle would be in Alsace-Lorraine, and instead positioned the 70,000 British troops to the northernmost end of their defence, close to Mons. Yet Mons was exactly where the 170,000 strong German First Army was heading while the German Second Army under von Bülow forced the nearby French Fifth Army under General Charles Lanrezac to retreat, leaving the British Expeditionary Force isolated and exposed.

Men of Mons

Neither the French nor Germans recognised that the BEF, though small, was an elite company of soldiers. The German assumption that the BEF was just 'a contemptible little army' was soon quashed, and the BEF support at Mons in Belgium slowed the German advance.

The German and British armies clashed on 23 August, though 16-year-old cyclist scout John Parr had been the first British casualty two days earlier. Despite being vastly outnumbered, British troops succeeded in defeating each German attack by superior marksmanship. Indeed, so fast was the British rifle fire that the German soldiers were convinced they were facing machine-guns. Yet General John French knew that tactically the British position was hopeless. The German army was a formidably large force that could launch flanking attacks on both sides, and so on 24 August the BEF retreated out of Belgium and into northern France.

The British and Belgians still held the valuable, isolated port of Antwerp for the time being. Although von Schlieffen had stated that troops defending ports would be only a minor irritation, von Moltke weakened the key right flank further, sending men there. Antwerp would not fall to the Germans until 10 October.

Here Comes Alsace-Lorraine Again

On 14 August the French army had launched Plan XVII, the anticipated mass attack on Alsace-Lorraine that General Joffre believed would show the world that French fighting spirit would triumph over all. Von Schlieffen had hoped that the French army would be able to be lured as far away from Paris as possible by a weak German defending force, yet his successor von Moltke had stationed a higher proportion of his men to this area than von Schlieffen had felt wise, in order to ensure that the French army would not prove successful.

The strongly defended German Sixth Army were equipped with heavy artillery that outranged the French equivalent, giving the Germans a decisive advantage. The German commander in the area, Prince Rupprecht, Crown Prince of Bavaria, was unwilling to sit idly by and allow the French to attack him, and pressed for the opportunity to counter-attack. On 20 August the Germans launched a counter-attack, forcing the French army back within two days. In a minor victory that was a strategic defeat, the bulk of the French army were retreating back towards Paris at the key time when the plan had been for them to be too far from the city to prevent its capture.

The Marne Event

On 23 August, when the BEF were holding the German advance at bay at Mons, Joffre realised how close to danger of losing France they were. He superbly redeemed his earlier blunder by methodically and miraculously redeploying the French army north to where the danger lay, forming the Sixth and Ninth armies under Generals Michel-Joseph Maunoury and Ferdinand Foch, while a new army was raised in Paris by General Joseph Galliéni.

The Allies were aided by the fledgling Royal Flying Corps (today's Royal Air Force), who informed the French of von Kluck's manoeuvring; the tactical advantage of aerial reconnaissance was a factor that von Schlieffen could not have predicted when his plan was being developed. Yet despite this, the BEF still almost faced total destruction during the retreat from Mons when it met an overwhelming German force at Le Cateau on 26 August.

It was at this time that von Moltke learned that Russia had launched a preliminary invasion into East Prussia. Fearing that this was the forefront of a full-scale invasion, potentially leading to a war on two fronts, von Moltke sent two army corps from his right flank back to Germany. Ironically, the immediate Russian threat was defeated while these men were still crossing Germany in the Battle of Tannenberg (26-30 August). Why did von Moltke disregard von Schlieffen's instruction to ignore such minor distraction until Paris had been conquered? It has been speculated that von Moltke believed that Paris would be easy pickings, with the BEF in retreat and the French army in tatters close to Alsace-Lorraine.

This led to a fatal decision by the Germans on 31 August. Instead of heading straight for Paris, General von Kluck and Field Marshal Karl von Bülow decided to ignore Paris for now and head east. They hoped to surprise and defeat the retreating French army, yet instead the French had positioned two armies on the River Marne, near Paris, to catch the now weakened advancing German army.

Joffre launched a tactical masterstroke. On 6 September, the start of the First Battle of the Marne, the French Sixth Army under Maunory struck at the flank of the German First Army. In order to meet this threat, von Kluck reinforced his right flank with men from his left, creating a gap between the German First and Second armies. The British Expeditionary Force broke through the gap, dividing the German armies. Yet the German First Army began to overwhelm the French Sixth Army, potentially leaving the British Expeditionary Force isolated between two much larger German armies and facing complete destruction.

You Wait Ages for a Bus to the Marne and 600 Arrive at Once...

By 8 September it looked as if the war was over and that the Germans had won. Then Galliéni saved the day with the fabled Taxis of the Marne. Knowing that Maunoury needed reinforcements desperately, Galliéni dispatched 6,000 men to the front in 600 taxis and buses, any vehicle suitable for transporting troops in. Von Moltke, positioned in Luxembourg, had lost contact with his troops and on 9 September, the order was given for the German army to retreat to more defensible ground at the River Aisne. The Germans had captured most of Belgium and much of northern France.

The Schlieffen Plan Abandoned

It was by now obvious to Germany that things had not gone according to the Schlieffen Plan. Kaiser Wilhelm had von Moltke replaced by Erich von Falkenhayn, who attempted to bypass the Allied troops and head north. Both sides tried to outflank each other in the phase of battle known as The Race to the Sea. The Germans saw the Channel ports as their main targets, and the Allies sought to protect these vital supply arteries at all costs. Once again, aerial reconnaissance was essential to the Allies, alerting them of outflanking manoeuvres from the Germans and allowing them to retaliate.

In November, the two sides fought each other to a standstill at the River Aisne. French troops failed to dislodge the Germans there, who had dug shallow trenches. The Battle of Aisne was the first occasion of trench warfare. In October the Germans had successfully captured Antwerp and Zeebrugge and then headed in strength for the key port of Ypres on 31 October. Ypres was defended by the BEF, and through the use of machine-guns and artillery, were able to withstand the assault of the superior German force.

Thus by late 1914 it was evident that a stalemate had been reached, with both sides deepening, fortifying and equipping trenches with barbed wire, artillery and bunkers in which to stay. These trenches stretched from the English Channel to Switzerland. For the war's duration neither side was willing to give an inch, even if it cost the lives of millions of men.

The Plan's Cost

By the close of 1914, the German army had captured almost all of Belgium and much of France at a cost of 120,000 men. France had lost 65,000, but of the 70,000 men of the British Expeditionary Force sent to France and kept out of the way from where battle had been expected, 55,000 had died. Yet Paris had been protected and the war was not over, and Germany faced what the plan had meant to prevent; a war on two fronts.

Controversies

The traditional view of the Schlieffen Plan has been to see it as the genius masterstroke of von Schlieffen, which would have inevitably succeeded had von Moltke not deviated from the plan and thus undermined it. Is this view fair and indeed accurate? To what extent was the plan von Schlieffen's, and what extent von Moltke's?

Many historians have argued that though von Schlieffen was renowned for his tactical prowess, he was unconcerned with political implications. Initial drafts of the Schlieffen plan proposed invading the Netherlands as well as Belgium. Although this would make moving troops and equipment easier, the political implication would ensure that the Dutch would ally themselves against Germany. Fighting in the Netherlands also would not only slow their advance when speed was key, but would have resulted in Germany losing access to the Dutch ports.

Many have suggested that the capture of Liège was von Moltke's masterstroke. Defenders of von Moltke have also suggested that von Schlieffen did not take into account that the French would be able to move troops in France quickly, having the benefit of an intact rail network, while German troops would need to traverse bridges, etc, destroyed by the defenders. He is also accused of not considering the possibility of trench warfare and the impact of barbed wire and machine-guns. Instead, von Schlieffen had been inspired by the rapid manoeuvres seen in the battle of Cannae, in which Hannibal defeated a much larger Roman force, as well as by Napoleon's strategies. These tactics did not take into account the armies of the early 20th Century, especially with regards to the development of aircraft and machine-guns. A modified version of von Schlieffen's plan inspired the highly effective Blitzkrieg attacks of the Second World War.