INTRODUCTION
What is the price of a mile? Every battle has a price in blood that must be paid for one side to win and the other to lose. Third Ypres had a high cost in blood for both sides that fully represents the futility and waste on the Western Front during the “Great War”. To deal with the constantly evolving battlefield takes leaders with imagination, adaptability, and to not only be able to see the big picture, but to understand it and act accordingly. They must also understand the terrain of the battlefield and to not run on assumption.
The “Great War” would also see a four-year grinding stalemate that would see carnage on an unfathomable scale. The battle for the Third Battle of Ypres (ee-pruh), also known as Passchendaele, is a prime example of the problems in the First World War. Located in the flat lowlands of Flanders, a province in Belgium, sat the town of Ypres. It was a crossroads that had been fought over throughout its history, but it would become infamous to men on both the allied and German side alike.
Map of the Ypres (Ieper) Salient, 1915– 1917, showing the location of… | Download Scientific Diagram
LOCATION
Flanders is a province in Belgium that is comprised of lowlands that are prone to flooding. To control this, a system of canals, locks, and levees were built throughout the area. These protective measures would be decimated by the heavy and repetitive shell fire and continuous combat. Add the rainfall of the area, and now the men were fighting in swampy mud as the earth tried to return Flanders to its original landscape.
The town of Ypres, the setting for this story, was a peaceful and prosperous town located 54.1 km from Dunkirk. Ypres is an ancient crossroads that was well connected with both roads and railways connecting it to other major European cities. This would make Ypres highly valuable strategically. The town was a home to the arts and education filled with resplendent buildings from the medieval and renaissance periods. In its center was the famous Cloth Hall, a hub of medieval trade that had been standing since 1304. Tragically, it would be obliterated during the battled for Ypres.
CLIMATE
With an average temperature of 51.8 degrees Fahrenheit (11 Celsius) and rainfall averaging 30 inches annuallyFlanders lives up to its Flemish meaning “flooded land”. Winters are severely cold, and summers are too short. During the fight for Passchendaele, the weather would play an important factor. In August and October 1917, twice the normal rainfall would drench the battlefield creating muddy quagmire.
BACKROUND
Before the war, all the combatants had developed plans in the event of a war, and in many ways, the leaders of each country or empire seemed chafing at the bit for it to start. For the Germans, it was the Schlieffen plan. The concept for it was simple: knock out the French in 6 weeks so that the full weight of the German Army could focus on the Russians. The plan, however, was not so simple. At the start of the War in 1914, the plan was put into motion. 2,000,000 Germans moved into neutral Belgium on the March to Paris. This of course triggered Great Britain to enter the war because of their treaty obligations to Belgium. Of course, in any plan, the opposing forces get a say, and the French launched their Plan XVII. German command panicked and transferred some of these men to counter the French offensive in Alsace-Lorraine.
Their trek through Belgium also took longer than expected which caused the so-called “Race to the Sea”. This last bit of maneuver warfare would end when the Belgian King flooded the coastal lowlands by opening the locks. This created an impassable obstacle stopping the German advance. This created the static lines that characterized the First World War. At Ypres, the British forces were forced to evacuate the highlands and dig into the lowlands. Through the first severe fighting at the first battle of Ypres, a deadly salient would develop. This meant that the Germans could hit the British from 3 sides, and since they commanded the heights, German artillery and infantry could attack down into the British lines.
In 1915, the Second Battle would be launched by the Germans. Here the first use of gas in warfare happened. German’s opened cylinders of Chlorine gas and the emanating cloud drifted over a 6-mile section of the line. The National Institute of Health states exposure to Chlorine Gas causes, “Acute exposure at high levels causes dyspnea, violent cough, nausea, vomiting, lightheadedness, headache, chest pain, abdominal discomfort, and corneal burns, in addition to the same symptoms of low-level acute exposure. Chronic exposure to chlorine gas can lead to chest pain, cough, sore throat, and hemoptysis.” The Algerian and African forces that received this dose of gas panicked and broke. Unfortunately for the Germans, this was just a diversionary attack for Austro-Hungarian efforts elsewhere and did not have the reserves to exploit the opportunity. On top of that, the newly arrived Canadians showed their meddle by stopping the German advance.
Sir Douglas Haig would replace Sir John French in 1915 and immediately began advocating for an offensive in Ypres. Unfortunately, the Germans would launch their Verdun offensive and Haig would launch the battle of the Somme to relieve the pressure on the French Army. During this battle, both sides would see 750,000 casualties. British forces would lose 60,000 on the first day! Haig would have to wait until 1917 to launch his Ypres Offensive.
OPPOSING FORCES
For the Entente, British and their Dominion Forces of India, Canada, the Australian and New Zealand Forces known as ANZACs with the help of a couple French Divisions would man the lines. They were led by Field Marshal Sir Douglas Haig. The armies in the field would be led by General Sir Hubert Gough, General Herbert Plumer, and Canadian General Arther Currie.
The German Army was led at this point by the Dynamic Duo of Paul Von Hindenburg, who was the German Chief of Staff under the Kaiser and Eric Ludendorff, the Chief Quartermaster. In Flanders, Bavarian Crown Prince Rupprecht was in command of the Germans. He would be labeled by Ludendorff a weak commander that was propped up by his staff.
THE LEADERS
British and Dominion:
Field Marshal Sir Douglas Haig was in overall command. Haig is an interesting character. Replacing Sir John French in December of 1915, he was convinced that the war would be won in Flanders and that he would win it! Haig would earn a reputation after the Somme as a butcher and did not enjoy the full support of the British Prime Minister David Lloyd George, who actively worked against Haig throughout the Passchendaele offensive.
Born in Edinburgh Scotland on 19 June 1861, Haig would choose the path of professional military officer. He attended Brasenose College in Oxford before attending the Royal Military Academy. He was a cavalryman who believed in the offensive. He would serve in the Boer War under Sir John French with whom he was a close friend. He would also serve staff roles such as the Director of Military Training and Chief of Staff for the Indian Military. He was a well-rounded and intelligent officer.
Haig was also deeply religious. He was a devout Presbyterian, and it is reported that he had his own chaplain that would travel with him. With this devotion also came his belief that he was preordained to lead his army to victory by the grace of God. Also, despite having earned a reputation after the Somme as a butcher that carelessly wasted the lives of his men, he cared deeply for those in his command. This would extend to after the war until his death as he advocated for and supported the men and veteran causes.
General Sir Hubert Gough was the commanding general of the British 5th Army. He was an Englishman born 12 August 1870. He studied at the Royal Military Academy after graduating from Eton College. He began his military career in the 16th Lancers in 1889 and gained a reputation as a brave and aggressive leader. He served with distinction during the Second Boer war and earned several promotions during it. By the beginning of the war in 1914, he was a Major General. He led the 3rd Cavalry Brigade of the British Expeditionary Force and saw action during the Retreat to the Mons as well as First Ypres.
He would assume command of the British 5th Army in March of 1916. He would lead them into the Battle of the Somme and would gain a reputation for his aggressive nature and willingness to push forward. He would also suffer severe criticism for the same reasons as this leadership style led to high casualties. For these reasons however, Haig would favor Gough over General Plumer.
General Herbert Plumer was the opposite of Gough. Born in Kent, England in 1857, Plumer would follow the career path of an engineer. These skills would use and be recognized for during his participation in the Second Boer War for his engineering prowess as well as leadership style. While Gough was aggressive and brash, Plumer would be meticulous and plan to the most minute detail. He was also a huge proponent of training the men. Before his actions in Flanders, he built large football field sized mockups of the battlefield and have his units walk the plan until they had it down.
Plumer’s meticulous and cautious ways made him popular with his men. This did not endear him to Haig as he preferred Goughs aggressive nature to Plumer’s caution. This would cause him to make the decision, though Plumer saw huge success with his assault on the Messines Ridge prior to the start of the Passchendaele offensive, to place Gough in command of the offensive.
General Arther Currie was a Canadian general from Ontario, Canada. Born in 1875, his career before the war was as a teacher and real estate agent. He was also a member of the 5th British Columbia Regiment of Garrison Artillery where he rose to the rank of Lieutenant Colonel. He journeyed to the war and in 1915 led his brigade with distinction in the First Battle of Ypres. He earned a promotion to Major General and assumed command of the 1st Canadian Division in September of 1915. He would gain further recognition leading his men in the successful attack on Vimy Ridge in 1917. He was innovative and able to adapt. He also looked after his troops earning their respect.
Germany:
Paul von Hindenburg was part of Germany’s First World War Dynamic Duo. He was a Prussian born in Poznan 2 October 1847. He would follow the Prussian tradition of military service and see his first action at the Battle of Konnigratz during the Franco Prussian war. In 1878 he would be appointed to the General Staff and reach the rank of General in 1905. He would retire in 1911 but return to service when the war broke out. He would lead the victories at Tannenberg and Masurian Lakes. Achieving the rank of Field Marshal in August 1916, he would supplant Field Marshal Erich Falkenhayn as the overall German commander.
Erich Ludendorff was the other half of Germany’s First World War Dynamic Duo. Born in 1865, Ludendorff would follow the Prussian path to military service. He would be part of the General Staff beginning in 1894 which gave him an intimate understanding of the German War Machine. He also was not a big proponent of peace as he viewed it as the break in between wars. His participation on the General Staff allowed him to participate in developing the Schlieffen Plan.
When the war broke out, he was assigned as quartermaster of the Second Army under General von Bulow. He then transferred to East Prussia as Chief of Staff to General Paul von Hindenburg. They would develop a close relationship and see many successes against the Russians at places like Tannenberg and Masurian Lakes. These two would then assume command of the German Army after Falkenhayn failed to achieve victory.
Crown Prince Rupprecht Maria Luitpold Ferdinand of Bavaria was born into Bavarian Royalty in 1869. As heir to the throne, he enjoyed all the trappings that came with it including the ears of German leaders. He would suffer many personal tragedies though and during the war would throw himself into his duties as an escape from his personal pain.
He began the war in command of the German 6th Army. He would be blamed for failing to trap and destroy the French Army in Alsace-Lorraine during the opening moves of the Schlieffen Plan. He would redeem himself and in 1916 become a Field Marshal. As such, he would be Haig’s opponent commanding the defense against Haig’s onslaught.
Ludendorff caused Rupprecht many headaches as he repeatedly tried to bypass him and give orders directly to his subordinates. After the war, he would go as far as planning blame on him for the loss on the western front, however Rupprecht was successful on an operational level.
TOOLS OF THE BATTLE
Infantry Weapons:
The infantry carried their sides standard weapons. British fighters carried the Lee Enfield .303 rifle into the battle with a bayonet affixed to the end. British warfighting put heavy stock into the Bayonet as it was more of a psychological tool of war than it was useful. British leaders would preach the “Spirit of the Bayonet” to ingrain its use to their soldiers. The Germans would go into battle sporting the 7.92mm Mauser Gewehr 98 which could also have a bayonet affixed to it. Both rifles were bolt action, but the Lee-Enfield carried twice the magazine capacity to the Mauser at 10 rounds. However, as a side note, British snipers preferred the Mauser over the Lee-Enfield as it could be fitted with optics. Both British and German officers carried pistols into battle. For the British, this was the Webley revolver and for the Germans it was the Luger P08. The Luger would be a prized trophy for the Entente soldiers.
The Machine Gun made its mark on the battlefields of the First World war but was primarily a defensive weapon as they were unwieldy large weapons that could not be carried into battle as they are today. The British Vickers Machine gun and The Maxim Machine Gun were two of the most prolific machine guns in this sector of the front. They required 4-6 men to operate and had a cyclic rate of 400-600 rounds per minute. The Germans created specialized machine gun companies into their army while the British integrated the machine gun into their units. It has been noted that 1 machine gun and its trained crew is equal to between 60 and 100 trained riflemen.
Other weapons that were commonplace were the trench mortar and hand grenades. Grenades were thrown by hand or could be launched by rifles and could be tossed into trenches and pillboxes to dislodge defenders. They could be detonated through a timed fuse or impact. The timed fuse was preferred by soldiers in the field and after a sharp learning curve, a safety pin would be commonplace to prevent accidental arming. German Stormtroopers would put grenades to effective use as they performed trench raids and assaults in the lead of offensives.
Trench Mortars were valuable to the infantry as they could be fired from the trenches and help support raids and harass the opposing force. Both sides would employ these tools with ruthless efficiency. Germany included the mortar in their prewar doctrine and had a large supply when marching into battle. The British were slow to grasp the concept but once they did, they put it to work enthusiastically.
Artillery:
Artillery was the most heavily used weapon of the First World War. It is estimated that 1.5 billion Artillery shells were fired during the war. During the Third Ypres offensive, 3000 guns would pummel German Defenses with 4.5 million shells. These guns would range from light easily moveable pieces to large heavy guns that could lob giant projectiles from a safe distance behind the lines. There were Long and Short Barreled Guns with the ability to fire at an almost flat trajectory while howitzers needed to lob shells at a high trajectory but were more effective for hitting the inside of a trench.
Artillery Shells also came in many shapes and sizes. There were shrapnel shells that would explode showering the recipient positions with fragments and ball bearings to inflict high casualties. High Explosive shells were used to bust defenses and cut barbed wire. The largest shell was fired by the German 420mm Howitzer named the “Jack Johnson”. This name was given as, like the boxer, could deliver a devastating punch. One shell could leave a crater 28 Feet across and 6 Feet deep at the center.
Aircraft:
Aviation made its combat debut on the battlefields of WWI. In the beginning they were used for observation and scouting. As the war progressed, they would evolve into fighters and bombers. The fighters would fly along with either bombers or observation aircraft and mix it up with the other sides fighters. During the Passchendaele offensive, these aircraft performed key roles in spotting German positions and batteries for the artillery. Of course, when the weather was bad, observation aircraft were grounded and not able to be used.
Terrors of the Battlefield:
To break the attrition of the trenches, weapons developers tried to develop fantastic wonder weapons. The first weapon was the Flamethrower. Germany had developed two models; one was a single man portable while the larger unit required a team. Like a dragon breathing fire, they would hose down the defenders with a liquified flame that would stick to anything. They would see its first successful use on a broad scale against the British in Flanders on 30 July 1915. The initial horror effectively broke the lines but the British recovered and stabilized their lines.
The next horror to be unleashed would be tried in 1915 at the Battle of First Ypres. The Germans would open canisters and release Chlorine gas. It drifted across no man’s land on the prevailing winds and devastated the defenders. Unfortunately for the Germans, they didn’t think it would work and missed an opportunity. By 1917, both sides would deliver gas via artillery, and it would be even worse than Chlorine gas. These toxins would cause their victims to choke and lungs to liquify. The worst incarnation, Mustard Gas would linger on the field to affect the defenders when they removed their mask when it was perceived safe.
Finally, though not as brutally awful as the last two, the Tank became a player on the field. These behemoths were first introduced on the Somme offensive in 1916 but were not successful due to design and mechanical flaws and not knowing how to properly use them. Improved models would be used during the Passchendaele offensive. Once again, the massive machines were rendered useless buy the muddy conditions of the battlefield.
COMMUNICATIONS
Communications during World War I presented many difficulties for the Generals that were commanding such large armies. Situational awareness during a battle is the key to success or failure. There were multiple means available to both sides during the war and came in many forms. There were runners, men who would traverse the hellscape and bring messages back and forth. This was not the most efficient means, but in many cases, especially during Third Ypres, these men were one of the only means to get messages back and forth, and because of battlefield conditions, many of them would not make it.
In addition to human runners, dogs and carrier pigeons would be used. Messages would be written out and attached to either animal with a special canister. Around 100,000 carrier pigeons would be used by all sides during the war with 95% effectiveness. Dogs could navigate the battlefield better and faster than human runners. A dog could traverse 10-15 miles within 2 hours and were trained to withstand the extreme cacophony of the battlefield. The British would employ 20,000 dogs during the war and the French around 15,000, of which around 5,000 perished. Canines were also able to perform other duties that pigeons could not. These would include sentry duty and helping find wounded, dead, or missing soldiers. The Germans reported in 1916 that dogs helped save 3,000 lives.
The field phone also made an appearance on the battlefield. Two field phone transceivers would be connected to each other or an exchange by a cable. The sound of a person’s voice would be converted into an electrical signal that could traverse through the cable at the speed of light. This form of communications would turn out to be unreliable during combat as artillery bombardments would inevitably cut the phone cables. To repair these lines or advance them with the infantry advance was also near impossible as snipers and artillery would target the linesman that attempted to repair or lay new cable.
Wireless communications were available though it was in its infancy. Most of these communications would be via telegraph. Many of these communiques would be intercepted by the opposing forces though and would in many cases spoil an operation. As the war progressed, this technology would become more man portable and efficient communications between artillery and the trenches or aircraft became more feasible.
TACTICS
Germany:
By this point in the war, Germany had gone on the defensive. The Germans had developed a defense in depth strategy. They would have multiple lines of trenches. These lines would consist of:
First line would be a lightly defended one with clear lines of withdrawal.
The second line would be more heavily defended.
The third trench line consisted of reserves.
This devastated the British Assaults during the Battle of the Somme. In addition, the German trenches were built of reinforced concrete and networked many concrete pill boxes containing machine guns and their crews with clear fields of fire. In between these trenches were barbed wire tangles. On top of this, the artillery was pre-registered to deal the most lethal blow from their deadly guns.
Great Britain:
Haig and Gough still were all in on the pre assault bombardment, though instead of many days’ worth they shortened it to a few hours. They would then follow on with a massive frontal infantry assault that would follow as closely behind the rolling artillery bombardment that would shift its way in front of them. There were of course many problems with this method. To begin with, the communications of the time were not conducive to this.
General Plumer’s went a different way that accounted for this. It was known as bite and hold. This enabled the men and artillery to work better in concert with each other. By choosing a series of smaller objectives, they take the objective with a withering fury from the artillery. Once the infantry took the objective, they would turn the defenses around and prep for a German counterattack. In the meantime, the Artillery guns would move forward to support the next objective. It truly showed the meticulous patience of an engineer versus the brute force of cavalrymen.
TRAINING
German training documents were few and far between during this time. It has been noted that on the lines, not much training happened, but units that rotated to the rear would train in reaction drills as well as practice marksmanship and with the bayonet.
British training was along the same lines except for General Plumer and General Curries. They stressed the importance of training and ensured that each Brigade, Company, Battalion, and Platoon knew their job. They would build mockups of enemy positions based upon aerial photos and intelligence from captured Germans and run through tactics and the plan until each man knew his job and that of their leaders and subordinates.
THE ACTION
Due to Germany’s unrestricted submarine warfare, Haig’s set the objective of this offensive to take the high ground around Ypres including Passchendaele Ridge and open the front to pave the way to take the sub pens on the North Sea coast of Belgium. To do this, he would build a force consisting of nine British and six French Divisions. These men would be led by Sir Hubert Gough and would be preceded by a cannonade of 3000 Artillery Pieces.
They would go up against a well-prepared German position that was designed with defense in depth in mind. This was because the Germans had settled upon a defensive war for the time being. The first line of trenches was lightly defended with a heavily defended second line and reserves behind them. This defensive strategy provided elasticity to the German positions to better absorb an attack.
The trenches were well built concrete and walled positions with pillboxes interwoven into the design to give maximum protection against both artillery and infantry attack. Included were bunkers for the men to hide in during bombardments. Artillery bombardments would open an attack so the defenders would hunker down and when the bombardment ended, they would rush out and man their posts to repel the attack.
Prior to the beginning of Haig’s Passchendaele offensive, General Plumer would lead an assault on Messines Ridge with British, Anzac, and Irish troops beginning on 7 July 1917. What began with the detonation of 19 Mines under the ridge, General Plumer’s’ divisions swept the ridge and took the German positions. To this point it was the most successful attack of the war. However, General Plumer was a cautious and meticulous leader and did not press the attack. This would lend to Haig’s decision to have General Sir Gough lead the Passchendaele attack.
In the early morning hours on 31 July 1917, 3000 guns opened with their barrage of death on the German positions. 4.25 million artillery shells would be fired in this barrage, announcing the attack on the positions. The element of surprise had already been lost when the Messines battle took place, this bombardment eliminated it. To make matters worse, the skies opened and dumped heavy rain on the battlefield. Since the artillery bombardments over the years had destroyed the flood controls, the battlefield was turned to, as one veteran described it, “a thick and sucking type of mud” The rain and clouds also prevented the Royal Flying Corp from taking to the skies and performing the important artillery spotting duties for which they were needed.
The initial attack was halted on 2 August with little gain and many casualties. They made further attempts on 6 and 10 August with the same results. The initial plan called for 6000-yard advance per day. Instead, by mid-august Gough’s soldiers managed a mere fraction of that. Unimpressed with Sir Goughs progress, he replaced the General with General Plumer after the former refused orders. Plumber took several weeks to reorganize and prepare the army for the next stage and launched his assault on the German lines on the Menin Road.
Compared to his peers, Plumer learned from the lessons of the Somme and other previous battles. He would build mockups of the battlefield the size of football fields and then walk each commander to the platoon level to be sure each one knew their assigned task. His plan made use of a bite and hold strategy. Using a creeping barrage, they would advance on a position, consolidate forces, move the artillery up, then move to the next target. The strategy proved very effective and threw the German defenders into disarray. Beginning on 20 September, Plumer’s army would take the Menin Road Bridge, then Polygon Wood and Broodseinde. This gave the British control of the Eastern ridges overlooking Ypres and gave them their stepping off point for Passchendaele.
The first battle of Passchendaele began on 10 October 1917. Unfortunately, they did not make much progress. The continued combat operations in addition to the use of mustard gas by the Germans defending the positions took its toll. Plumer’s army was worn out. Rain had also begun again, causing added problems and misery to the battles. In all, the British would make 3 concerted efforts against the German positions on Passchendaele ridge. Finally, on 6 November, the British took the position and ceased the attack on 11 November.
SIGNIFICANCE OF THE ACTION
In the United States Army Field Manual FM 3-0 Operations, they list 9 Principles of War. These are Clear Objectives, to Seize and Maintain the Offensive, Mass your Forces, Utilize Surprise, Maneuver, and Economy of Force, Maintain Security, Unity of Command, and keep it Simple. How does the plan and action hold up to the principles of war taught today? Not well.
Haig had clear objectives, but they were not manageable. Maneuver was non-existent as they were all frontal attacks. The attack by Plumer in June on Messines Ridge should have been immediately followed with the offensive against Passchendaele. Since it wasn’t, the initiative was lost, and any further surprise was squandered with the preliminary bombardment. Unity of Command was a problem from the start. The British Prime minister David Lloyd George worked constantly to undermine Haig before and during the battle. Haig’s Generals also had collisions of ego from time to time. They massed their forces but did not wisely use them. General Plumer was the only one who seemed able to adapt to the battlefield and learn lessons as seen by his bite and hold strategy.
Jocko Willink often discusses the problem of Ego on his podcast. On Episode 215, he states, “You’ll never be free unless you tell yourself the truth”. Haig could have used these lessons. He kept believing falsely in his assumption that he had the Germans on the ropes. There is evidence of him being surrounded by yes men who would not tell him the truth to not hurt his ego, but at the end of the day it was his ego that failed his men and wasted many of their lives needlessly. And he was not the only one. Prime Minister Lloyd George’s ego would create a lot of problems for Haig. An example of this was his constant attempts at trying to shift Haig’s resources to other sectors reducing Haig’s ability to bring the full fight to the Germans.
Haig would claim the attack a success. In a way, it was. Haig reached his stated objective of taking Passchendaele and for the first time since 1914, they controlled the high ground. The cost was high. Though neither side will ever know the exact numbers, we will use the figures from Winston Groom’s “A Storm in Flanders” which places British and Allied Casualties at 350,000 and 335,000 German. With those numbers, total casualties for all combatants are 685,000 dead or wounded from this battle.
CONCLUSION
At the end of the day, this battle will continue to be analyzed and the controversy of the battles success or failure will never end. There is a lot of bias on both sides, and at the end of the day, especially in a world of satellites, cyberspace, drones, and speed of light communications, the perspective of the participants is important.
To answer, “What is the price of a mile?” The Battle for Passchendaele saw the allies advance 5 miles. That makes the price of a mile 137,000 lives. Broken down for each side, 70,000 allied and 67,000 German. Oh, in 1918, the British army evacuated Passchendaele without a fight!
Bibliography
Primary:
Boff, Jonathan. Haig’s Enemy. Oxford: Oxford University Press, 2018
FM3-0 Operations. Army Publications. Washington DC: Army Press, 2001.
Haig, Douglas, Edited by Sheffield, Gary and Bourne, John. Diaries and Letters: 1914-1918. London: Orion Books LTD, 2005
Harvey, Trevor. “Biographical Notes on Sir Hubert Gough.” Journal of the Society for Army Historical Research 96, no. 386 (2018): 179–81.
“Voices of the First World War: Passchendaele”. Imperial War Museums, Accessed: 18 June 2024.
Secondary:
Bruton, Elizabeth. “Signaling at the Battle of Passchendaele, July to November 1917.” Innovating in Combat. Accessed: 22 May 2024.
“Rupprecht, Crown Prince of Bavaria”. 1914-1918 Online. Accessed: 18 June 2024.
Burke, Tom. “Brotherhood among Irishmen? The Battle of Wijtschate-Messines Ridge, June 1917.” History Ireland 15, no. 5 (2007): 28–33.
Beardsley, Eleanor. WWI Munitions Still Live Beneath Western Front. NPR. 11 November 2007.
Duffy, Michael. First World War.com, 22 August 2009.
DVA (Department of Veterans Affairs). “Third Battle of Ypres 31 July-10 November 1917. Australia: DVA Anzac Portal, 2023. Accessed 20 May 2024.
Steenhard, Rens.” Carrier Pigeons in the First World War.” Peace Palace Library. 29 July 2014.
Sir Arthur Currie.” Canadian War Museum. Accessed: 18 June 2024.
Western Front Association. Accessed: 18 June 2024
Lupfer, Timothy J. The Dynamics of Doctrine: The Changes in German Tactical Doctrine During the First World War.” Fort Leavenworth: U.S. Army Command and General Staff College, 1981.
Willis, Mathew. “Dogs in the Trenches of World War I” JSTOR Daily. 8 November 2021.
Hussey, John. “The Movement of German Divisions to the Western Front, Winter 1917–1918.” War in History 4, no. 2 (1997): 213–20.
Ham, Paul. Passchendaele: Requiem for Doomed Youth. Australia: Random House, 2016.