At the commencement of World War I, Germany wanted to avoid fighting on two fronts by defeating France first and then turning its attention to Russia, France's ally. The initial German onslaught was successful, but there were not enough reinforcements available to keep the momentum going. The French and British launched a counter-offensive at the Marne (6-10 September 1914), and the Germans fled after several days of fierce fighting.

The inability of Germany to beat the French and British at the Marne had significant strategic ramifications. The Russians mobilized faster than the Germans expected and launched their first offensive just two weeks after the war began. The Battle of Tannenberg in August 1914 ended in German triumph, but the combination of German victory in the east and defeat in the west ensured that the war would be long and drawn out, spanning multiple fronts.

On the Western Front, the Battle of the Marne also signaled the end of mobile combat. Following their withdrawal, the Germans re-engaged Allied forces on the Aisne, where the action slowed and became trench warfare.

The massive casualties caused by modern weapons in the early months of the war shocked the world. For the year 1914, total losses on all fronts surpassed five million, with a million men killed. This was a level of ferocity unheard of in any prior conflict. Because of the high number of deaths in open fighting, men on all fronts began to build trenches to shield themselves, which would dominate the Western Front until 1918.

When: 1914

The Battle of Gallipoli, which lasted eight months and was initiated by a coalition of British, French, Indian, New Zealand, Australian, and Canadian forces to eliminate Turkish Ottoman Empire forces siding with Germany, was one of the major battles of World War I. The British and their allies planned to sail a massive fleet through the Dardanelles, a 65-mile sea channel connecting the Mediterranean with Istanbul, the Ottoman capital. The plan's goal was to compel the Ottoman Empire to submit. The strategy failed badly, owing in part to the allies' out-of-date fleet and the many ships sunk by Ottoman artillery and mines.

The Battle of Gallipoli claimed the lives of 58,000 Allied men. There were 29,000 British and Irish troops, as well as 11,000 Australian and New Zealand troops. There were also over 300,000 Ottoman Turkish troops killed and injured on both sides. The battle of Gallipoli was memorialized in Mel Gibson's 1981 film Gallipoli. Mustafa Kemal Ataturk, the lieutenant colonel of the 19th Turkish division, rose to prominence as a result of the Ottoman triumph. In 1923, he became the modern-day Turkish Republic's founding father.

When: 1915 - 1916

The Battle of Jutland, dubbed the "Greatest Naval Battle of the First World War," took place on the 31st of May and 1st of June in 1916, pitting the British against the German fleet of "dreadnought" battleships. It was a brutal conflict involving 250 ships and around 100,000 soldiers. The engagement took place in the North Sea, and German Admiral Reinhard Scheer intended to include both Admiral Sir David Beatty's Battlecruiser Force and Admiral Sir John Jellicoe's Grand Fleet in the conflict. Scheer's strategy was to annihilate Beatty's force before Jellicoe arrived. According to Imperial War Museum documents, this was prevented when the British were forewarned by their code-breakers and sent their forces to sea early. Those first encounters between Beatty’s force and the German high seas fleet caused losses of several ships.

The Germans sank HMS Indefatigable and HMS Queen Mary, as well as Beatty's flagship, the HMS Lion. After German shells hit their ammunition magazines, they blew up. Beatty retreated in defeat until Jellicoe arrived with the main fleet. The outgunned Germans withdrew back to their homeland. The British suffered 14 shipwrecks and 6000 casualties, while the Germans suffered 11 shipwrecks and over 2500 casualties. The Germans never really threatened British control of the North Sea after that. It also ensured British control of maritime waterways, allowing Britain to establish a blockade that led to Germany's defeat in 1918. The Battle of Jutland was the subject of many documentaries, the most recent of which was broadcast by the British Broadcasting Corporation (BBC) in 2016.

When: 1916

The Battle of Verdun, which began on February 21st and ended on December 19th, 1916, was one of the longest and most violent conflicts of World War One.

This conflict involved nearly three-quarters of the French army. According to sources from the Verdun Memorial Museum, it began when the German forces, led by General Erich Von Falkenhayn, began pounding French forts and trenches with artillery fire from 1200 guns. To allow his forces to deploy, the General sought to put an end to the trench warfare that began in 1914. The Germans broke through the French front lines and took over Fort Douaumont without a struggle in the early days. Despite severe shelling, the French infantry remained in their posts and resisted the Germans. Henri Petain, a French general, was assigned to defend Verdun and command the men. He increased traffic on the Bar-le-Duc to Verdun route, which transported men, supplies, and weaponry to the battlefield. This route was utilized by over 4000 trucks, 2000 vehicles, 800 ambulances, 200 buses, and vans. This guaranteed that when the Germans attacked the left bank of the Meuse on March 6, 1916, despite severe combat on Le Mort Homme that lasted into April, they were unable to break the French front line. However, by the end of June, the Germans had taken Fort Vaux.

When: 1916

A large cooperative operation involving British and French soldiers against the Germans took place in the Somme area of northern France from July 1st to November 18th, 1916. The Battle of the Somme was planned by coalition commanders, French Joseph Joffre and British General Douglas Haig, in December 1915 to counter the German advance at Verdun. According to Imperial War Museum documents, the British lead the onslaught and encountered a German defense that had been constructed over months. Despite a seven-day bombardment prior to the 1st July onslaught, the British were unable to accomplish the victory that General Haig's military leadership had hoped for, despite sending 100,000 soldiers to overrun German fortifications. The Somme became a battle of attrition, with the British capturing only three square miles of ground in 141 days.

Over a million people were wounded, captured, or murdered by the opposing forces. But it was the 57,470 fatalities on the first day of the battle of the Somme that impacted the British psyche, with 19,240 army personnel killed. It was the bloodiest day in British military history as a result. The German army also suffered 6000 casualties on that first day, many of them at the hands of French forces stationed on the Somme's southern flank. According to analysts, the British casualties on the Somme were caused by the employment of unskilled volunteers as soldiers and insufficient artillery in the seven-day bombardment, which did not harm German soldiers who were safe in deep trenches. The British also underestimated the battle-hardened German men nestled up in the trenches, who were well-drilled and armed. As a result, the German forces were able to regroup, counterattack, and reclaim most of the ground they had previously lost. Over a million troops from the French, British, and German armies were killed or wounded in just five months.

When: 1916

The Russian Army had suffered a string of humiliating defeats in the first year of the war, but the Brusilov Offensive (4 June - 20 September 1916) would go down in history as the most successful Russian offensive, one of the most successful breakthrough operations, and one of the major battles of World War I.

The operation was named after the Russian general who conducted it, Aleksei Brusilov, and it employed tactics that would later prove successful on the Western Front. Brusilov exploited weak locations with a brief, fast artillery bombardment and shock troops, helping to restore the attack's element of surprise.

The offensive was timed to coincide with the British attack on the Somme and was part of a larger plan to alleviate pressure on the French at Verdun as well as the entire Western Front. The Russian onslaught also diverted Austro-Hungarian forces away from the Italian Front, increasing pressure on the Austro-Hungarian Army, which was already strained and demoralized.

In order to support its friend, Germany was forced to shift troops to the Eastern Front. This was part of an expanding pattern of Austria-increasing Hungary's reliance on Germany, putting a pressure on German resources.

Brusilov's feat was never duplicated by the Russians. It was their final major offensive of the war, and it resulted in general military and political weakness for both Russia and Austria-Hungary. The war sparked political and social discontent, resulting in revolution and the Russian Army's utter defeat.

When: 1916

The Battle of Passchendaele, also known as the Third Battle of Ypres, is remembered for its large number of casualties as well as the pervasive mud. This combat took place in Ypres, a town on the British side of the line. Following a warning that a German blockade would hamper British war efforts, Field Marshal Douglas Haig yearned for a British offensive in Flanders. He planned to reach the Belgian shore and destroy the German submarines that were stationed there. The British were bolstered by the success of an offensive on the conquest of the Messiness Ridge in June 1917. On the 31st of July, the British infantry launched an offensive on Ypres. The continual shelling dissolved the clay into the soil, causing drainage systems to collapse. Unlike the right wing, the attack's left wing was successful. In the days that followed, the greatest rains in 30 years converted loose soil into mud, clogging weapons and halting tank operations. Many men and animals perished as a result of the mud.

British attacks began on August 16th, but with no success. For a month, there was a stalemate, but attacks began on September 20th when the weather improved. The British captured the ridge east of Ypres in the battles of Menin, Road Ridge, and Polygon Wood on September 26th, as well as the Battle of Broodseinde on October 4th. The British and Canadian soldiers took control of what was left of Passchendaele hamlet on November 6. This provided Haig with an excuse to call a halt to the offensive and declare victory. Despite the fact that Passchendaele was only five miles from the start of the Haig-led onslaught. The three-month fight of Passchendaele claimed the lives of 325,000 British and allied troops and 260,000 Germans.

When: 1917

The German Spring Offensives (21 March - 18 July 1918) were a calculated bet on Germany's part in an attempt to permanently swing the balance on the Western Front. On the rainy and misty morning of March 21, 1918, Operation 'Michael,' the first of the offensives, began. A massive concentration of German artillery, gas, smoke, and infantry greeted British and Allied soldiers. The German Army made unheard-of gains in terms of kilometers rather than yards.

Following Russia's defeat, Germany focused all of its resources on the Western Front. They were up against exhausted Allied forces that had mostly been on the offensive for the previous three years, had not completely structured their defenses in depth, and were beginning to suffer from manpower shortages.

The Allied line bowed but did not break in the face of the onslaught. As isolated pockets of defenders attempted to impede the German assault, the battle became unusually open. As a result, Field Marshal Sir Douglas Haig issued a special order of the day on 11 April, using the phrase 'Backs to the Wall' to describe the desperate yet persistent combat that needed to be sustained.

The German offensives, however, were tactical victories but strategic disasters. The offensive had no clear objective other than to rip a hole in the Allied line and focus on the British. Where the Allies were most willing to lose ground, the Allies made the most gains. The number of German casualties was considerable, especially among the best battalions. To better coordinate a united defense, the Allies appointed Marshal Ferdinand Foch as Allied Generalissimo. By early July, the tide had turned, and the German offensives had come to a standstill.

When: 1918

The Battle of Amiens (8-11 August 1918) marked the start of the Hundred Days campaign, a four-month period in which the Allies triumphed. Following their survival of the German Spring Offensives, Allied forces launched their own counter-offensive, and from the summer of 1918 onwards, they were continuously on the move.

The Allies had developed advanced operating procedures that best utilized the material power at their disposal as a result of their previous hard experiences. The British Expeditionary Force (BEF) was at the vanguard, combining scientific artillery systems with flexible infantry firepower, as well as the deployment of tanks and aircraft. These combined arms tactics were supposed to serve as a model for the future.

The Battle of Amiens began on August 8th, after the initial Allied counter-attacks began in July. Secret preparations insured surprise, and the BEF gained seven kilometers in one day, which German General Erich Ludendorff dubbed "the German Army's black day." But, unlike previous offensives, the Allies now knew when to call it a day. The battle at Amiens was halted after four days of fighting when its effects faded, and a new onslaught was launched elsewhere. This established a successful pattern. The German forces were driven back by a series of synchronized hammer attacks.

When necessary to penetrate German defenses, Allied attacks were adaptable, relying on surprise and mobility as well as the deliberate tactics of 1917. Although there were still many casualties, the advantages were decisive. The German Army was no longer capable of fighting by November. It had been relegated to the 1914 battlefields and was only travelling in one direction. The Hundred Days was a spectacular display of military might that resulted in Allied victory.

When; 1918

The Battle of Megiddo (19-25 September 1918) marked the start of the Sinai and Palestine Campaign's final British-led attack. It was able to defeat the Ottoman Turks and their German allies by successfully combining cavalry, infantry, artillery, armored vehicles, and aircraft. It was the start of a string of significant Allied triumphs that eventually saw the Ottoman Turkish troops crumble and withdraw from the war, and it is also one of the major battles of World War I.

Under the command of British Lieutenant-General Sir Edmund Allenby, the Egyptian Expeditionary Force (EEF) began an operation against Ottoman soldiers in northern Palestine and the Jordan Valley on September 19. Allenby's strategy was to envelop Ottoman forces reassembling in the Megiddo area and cut off their escape routes. An effective Allied deception effort had persuaded Ottoman soldiers that an Allied onslaught would come from the east, leaving Ottoman positions in coastal Palestine exposed and out manned.

The onslaught began with a powerful but brief artillery barrage. With an advance of over 30 kilometers on the first day, British and Commonwealth forces soon smashed through the damaged Ottoman lines. The Desert Mounted Corps then pushed through holes in the Ottoman fortifications to encircle them. Under the pressure of the Allied offensive, the Ottoman Eighth and Seventh Armies disintegrated, with tens of thousands surrendering.

The victory at Megiddo paved the path for Australian troops to invade Damascus on October 1. Other strategically significant cities were seized by the Allies in the weeks that followed. On October 30, the Ottoman Empire attempted to reach a peace agreement with the Allies, and an armistice was signed in Mudros, with hostilities ending the next day at 12 noon. This was also after the defeat of Turkish forces in Mesopotamia by Britain and her allies.

When: 1918

The Battle of Cambrai, fought in northern France between the British and Germans from November 20 to December 4, 1917, was the first time battle tanks were utilized in battle on a large scale. Tanks were used in conjunction with air power and heavy artillery. About 476 tanks were manufactured by the nineteen British divisions, 324 of which were battle tanks and the rest were supply and service vehicles. The combat began on the morning of November 20, 1917, when the British Third Army launched an offensive on the Germans in the direction of Cambrai. Initially, eight British divisions surprised three German divisions and captured 7500 Germans. To alleviate pressure on French forces, the third army, under by General Julian Byng, struck the German Hindenburg defensive line. Despite initial victories, the British were eventually overwhelmed by German counterattacks, which were aided by terrible weather.

The British had advanced 5 miles and captured a number of settlements. Over half of the British tanks were destroyed before the conclusion of the first day. Even as the conflict intensified, this halted the British advance. The British reached the summit of Bourlon Ridge on October 28th. However, German forces launched a counter-offensive two days later, employing heavy artillery and infantry tactics. According to the Imperial War Museum, the British army was forced to retreat after only capturing the villages of Havrincourt, Ribécourt, and Flesquières. In the years that followed, the Battle of Cambrai paved the door for the adoption of complex weapons tactics and armored warfare. Both the Germans and the British suffered 45,000 casualties.

When: 1917

The Battle of Caporetto, also known as the 12th Battle of the Isonzo, saw Austro-Hungarian and German forces surprise Italian soldiers in northern Isonzo and break through their fortifications. Following Italy's defeat, Luigi Cadorna was fired as Chief of Staff, and the government was replaced. After the 11th battle of the Isonzo, led by Cadorna, exhausted Austrian and Hungarian allies faced collapse in Gorizia, their leader Arz Von Straussenberg sought assistance from the German Third Supreme Command, led by Paul Von Hindenbrug, and Erich Ludendorff, to mount a combined offensive. When Cadorna learnt of German involvement through deserters and aerial observation in mid-September 1917, he halted his own offensive and took a defensive position. Under the command of Otto vob Below, six German divisions augmented the Third Supreme's nine Austrian army divisions.

For the coordinated onslaught, the Germans chose a 25-kilometer-long line in front of Caporetta, north of Gorizia along the Isonzo, as their chosen site of the attack. The Italian commander Luigi Capello was told to create a defensive line, but instead massed his soldiers to attack Von Below's army on the southern flank, east of Gorizia. The combined Austrian, Hungarian, and German forces struck and surprised the Italians at Tolmino at 2 a.m. on October 24, 1917. The attack immediately through the Italian Second Army's defenses. The German, Austrian, and Hungarian forces had advanced 25 kilometers, broke the Italian lines with grenades and flamethrowers, and used infiltration tactics by the end of the day. Below, attacks on the River Tagliamento put the majority of Italian forces in jeopardy, prompting Capello to urge a withdrawal, which was overruled by Cadorna. Cadorna forced the majority of the Italian forces to cross the river, which took four days and ended on October 30, 1917. The Austrian, Hungarian, and German supplies had begun to run out, and they were unable to mount a new onslaught. As a result, Cadorna ordered the withdrawal of Italian soldiers to the Piave River. The Italians lost 300,000 people, 90 percent of them were prisoners. As a result, Cadorna was fired and replaced with Marshal Armando Diaz. In place of incumbent Paolo Boselli, a new Prime Minister, Vittorio Orlando, was sworn in.

When: 1917