Humanities › History & Culture World War I: Opening Campaigns Moving to Stalemate Share Flipboard Email Print World War I: An Introduction Introduction Origins A Short Timeline Pre-1914 The Top 5 Causes Leading Up to WWI Assassination of Archduke Franz Ferdinand Check Your Knowledge: WWI Origins The Battlefront Opening Campaigns A Stalemate Ensues America Joins the Fight Battle to the Death Check Your Knowledge: WWI Battles The Home Front Women and WWI The American Economy in WWI Aftermath and Consequences The Treaty of Versailles Consequences of WWI Check Your Knowledge: WWI Aftermath French cavalry marching through Paris, 1914. Public Domain By Kennedy Hickman Military and Naval History Expert M.A., History, University of Delaware M.S., Information and Library Science, Drexel University B.A., History and Political Science, Pennsylvania State University Kennedy Hickman is a historian, museum director, and curator who specializes in military and naval history. He has appeared on The History Channel as a featured expert. our editorial process Facebook Facebook Kennedy Hickman Updated February 19, 2020 World War I erupted due to several decades of rising tensions in Europe caused by increasing nationalism, imperial competition, and arms proliferation. These issues, along with a complex alliance system, required only a small incident to put the continent at risk for a major conflict. This incident came on July 28, 1914, when Gavrilo Princip, a Yugoslav nationalist, assassinated Archduke Franz Ferdinand of Austria-Hungary in Sarajevo. Responding to the murder, Austria-Hungary issued the July Ultimatum to Serbia which included terms that no sovereign nation could accept. The Serbian refusal activated the alliance system which saw Russia mobilize to aid Serbia. This led to Germany mobilizing to aid Austria-Hungary and then France to support Russia. Britain would join the conflict following the violation of Belgium's neutrality. Campaigns of 1914 With the outbreak of the war, the armies of Europe began mobilizing and moving towards the front according to elaborate timetables. These followed elaborate war plans that each nation had devised in the preceding years and the campaigns of 1914 were largely the result of nations attempting to execute these operations. In Germany, the army prepared to execute a modified version of the Schlieffen Plan. Devised by Count Alfred von Schlieffen in 1905, the plan was a response to Germany's likely need to fight a two-front war against France and Russia. Schlieffen Plan In the wake of their easy victory over the French in the 1870 Franco-Prussian War, Germany viewed France as less of a threat than its large neighbor to the east. As a result, Schlieffen decided to mass the bulk of Germany's military strength against France with the goal of scoring a quick victory before the Russians could fully mobilize their forces. With France defeated, Germany would be free to focus their attention to the east (Map). Anticipating that France would attack across the border into Alsace and Lorraine, which had been lost during the earlier conflict, the Germans intended to violate the neutrality of Luxembourg and Belgium to assault the French from the north in a massive battle of encirclement. German troops were to defend along the border while the right wing of the army swung through Belgium and past Paris in an effort to destroy the French army. In 1906, the plan was altered slightly by Chief of the General Staff, Helmuth von Moltke the Younger, who weakened the critical right wing to reinforce Alsace, Lorraine, and the Eastern Front. Rape of Belgium After quickly occupying Luxembourg, German troops crossed into Belgium on August 4 after King Albert I's government refused to grant them free passage through the country. Possessing a small army, the Belgians relied on the fortresses of Liege and Namur to halt the Germans. Heavily fortified, the Germans met stiff resistance at Liege and were forced to bring up heavy siege guns to reduce its defenses. Surrendering on August 16, the fighting delayed the Schlieffen Plan's precise timetable and allowed the British and French to begin forming defenses to oppose the German advance (Map). While the Germans moved on to reduce Namur (August 20-23), Albert's small army retreated into the defenses at Antwerp. Occupying the country, the Germans, paranoid about guerilla warfare, executed thousands of innocent Belgians as well as burned several towns and cultural treasures such as the library at Louvain. Dubbed the "rape of Belgium," these actions were needless and served to blacken Germany's and Kaiser Wilhelm II's reputation abroad. Battle of the Frontiers While the Germans were moving into Belgium, the French began to execute Plan XVII which, as their adversaries predicted, called for a massive thrust into the lost territories of Alsace and Lorraine. Guided by General Joseph Joffre, the French army pushed the VII Corps into Alsace on August 7 with orders to take Mulhouse and Colmar, while the main attack came in Lorraine a week later. Slowly falling back, the Germans inflicted heavy casualties on the French before halting the drive. Having held, Crown Prince Rupprecht, commanding the Sixth and Seventh German Armies, repeatedly petitioned for permission to go on the counter-offensive. This was granted on August 20, even though it contravened the Schlieffen Plan. Attacking, Rupprecht drove back the French Second Army, forcing the entire French line to fall back to the Moselle before being stopped on August 27 (Map). Battles of Charleroi & Mons As events were unfolding to the south, General Charles Lanrezac, commanding the Fifth Army on the French left flank became concerned about German progress in Belgium. Allowed by Joffre to shift forces north on August 15, Lanrezac formed a line behind the Sambre River. By the 20th, his line extended from Namur west to Charleroi with a cavalry corps linking his men to Field Marshal Sir John French's newly arrived, 70,000-man British Expeditionary Force (BEF). Though outnumbered, Lanrezac was ordered to attack across the Sambre by Joffre. Before he could do this, General Karl von Bülow's Second Army launched an assault across the river on August 21. Lasting three days, the Battle of Charleroi saw Lanrezac's men driven back. To his right, French forces attacked into the Ardennes but were defeated on August 21-23. As the French were being driven back, the British established a strong position along the Mons-Condé Canal. Unlike the other armies in the conflict, the BEF consisted entirely of professional soldiers who had plied their trade in colonial wars around the empire. On August 22, cavalry patrols detected the advance of General Alexander von Kluck's First Army. Required to keep pace with the Second Army, Kluck attacked the British position on August 23. Fighting from prepared positions and delivering rapid, accurate rifle fire, the British inflicted heavy losses on the Germans. Holding until evening, French was forced to pull back when the French cavalry departed leaving his right flank vulnerable. Though a defeat, the British bought time for the French and Belgians to form a new defensive line (Map). The Great Retreat With the collapse of the line at Mons and along the Sambre, Allied forces began a long, fighting retreat south towards Paris. Falling back, holding actions or unsuccessful counterattacks were fought at Le Cateau (August 26-27) and St. Quentin (August 29-30), while Mauberge fell on September 7 after a brief siege. Assuming a line behind the Marne River, Joffre prepared to make a stand to defend Paris. Angered by the French proclivity for retreating without informing him, French wished to pull the BEF back towards the coast, but was convinced to stay at the front by War Secretary Horatio H. Kitchener (Map). On the other side, the Schlieffen Plan continued to proceed, however, Moltke was increasingly losing control of his forces, most notably the key First and Second Armies. Seeking to envelop the retreating French forces, Kluck and Bülow wheeled their armies to the southeast to pass to the east of Paris. In doing so, they exposed the right flank of the German advance to attack. First Battle of the Marne As the Allied troops prepared along the Marne, the newly formed French Sixth Army, led by General Michel-Joseph Maunoury, moved into position west of the BEF at the end of the Allied left flank. Seeing an opportunity, Joffre ordered Maunoury to attack the German flank on September 6 and asked the BEF to assist. On the morning of September 5, Kluck detected the French advance and began turning his army west to meet the threat. In the resulting Battle of the Ourcq, Kluck's men were able to put the French on the defensive. While the fighting prevented the Sixth Army from attacking the next day, it did open a 30-mile gap between the First and Second German Armies (Map). This gap was spotted by Allied aircraft and soon the BEF along with the French Fifth Army, now led by the aggressive General Franchet d’Esperey, poured in to exploit it. Attacking, Kluck almost broke through Maunoury's men, but the French were aided by 6,000 reinforcements brought from Paris by taxicab. On the evening of September 8, d'Esperey assaulted the exposed flank of Bülow's Second Army, while French and the BEF attacked into the growing gap (Map). With the First and Second Armies being threatened with destruction, Moltke suffered a nervous breakdown. His subordinates took command and ordered a general retreat to the Aisne River. The Allied victory at the Marne ended German hopes of a quick victory in the west and Moltke reportedly informed the Kaiser, "Your Majesty, we have lost the war." In the wake of this collapse, Moltke was replaced as chief of staff by Erich von Falkenhayn. Race to the Sea Reaching the Aisne, the Germans halted and occupied the high ground north of the river. Pursued by the British and French, they defeated Allied attacks against this new position. On September 14, it was clear that neither side would be able to dislodge the other and the armies began entrenching. At first, these were simple, shallow pits, but quickly they became deeper, more elaborate trenches. With the war stalled along the Aisne in Champagne, both armies began efforts to turn the other's flank in the west. The Germans, eager to return to maneuver warfare, hoped to press west with the goal of taking northern France, capturing the Channel ports, and cutting the BEF's supply lines back to Britain. Using the region's north-south railways, Allied and German troops fought a series of battles in Picardy, Artois and Flanders during late September and early October, with neither able to turn the other's flank. As the fighting raged, King Albert was forced to abandon Antwerp and the Belgian Army retreated west along the coast. Moving into Ypres, Belgium on October 14, the BEF hoped to attack east along the Menin Road, but were halted by a larger German force. To the north, King Albert's men fought the Germans at the Battle of the Yser from October 16 to 31, but were halted when the Belgians opened the sea-locks at Nieuwpoort, flooding much of the surrounding countryside and creating an impassable swamp. With the flooding of the Yser, the front began a continuous line from the coast to the Swiss frontier. First Battle of Ypres Having been halted by the Belgians at the coast, the Germans shifted their focus to assaulting the British at Ypres. Launching a massive offensive in late October, with troops from the Fourth and Sixth Armies, they sustained heavy casualties against the smaller, but veteran BEF and French troops under General Ferdinand Foch. Though reinforced by divisions from Britain and the empire, the BEF was badly strained by the fighting. The battle was dubbed the "The Massacre of the Innocents of Ypres" by the Germans as several units of young, highly enthusiastic students suffered frightful losses. When the fighting ended around November 22, the Allied line had held, but the Germans were in possession of much of the high ground around the town. Exhausted by the fall's fighting and the heavy losses sustained, both sides began digging in and expanding their trench lines along the front. As winter approached, the front was a continuous, 475-mile line running from the Channel south to Noyon, turning east until Verdun, then slanting southeast towards the Swiss border (Map). Though the armies had fought bitterly for several months, at Christmas an informal truce saw men from both sides enjoying each other's company for the holiday. With the New Year, plans were made to renew the fight. Situation in the East As dictated by the Schlieffen Plan, only General Maximilian von Prittwitz's Eighth Army was allocated for the defense of East Prussia as it was expected that it would take the Russians several weeks to mobilize and transport their forces to the front (Map). While this was largely true, two-fifths of Russia's peacetime army was located around Warsaw in Russian Poland, making it immediately available for action. While the bulk of this strength was to be directed south against Austria-Hungary, who were only fighting a largely one-front war, the First and Second Armies were deployed north to invade East Prussia. Russian Advances Crossing the frontier on August 15, General Paul von Rennenkampf's First Army moved west with the goal of taking Konigsberg and driving into Germany. To the south, General Alexander Samsonov's Second Army trailed behind, not reaching the border until August 20. This separation was enhanced by a personal dislike between the two commanders as well as a geographic barrier consisting of a chain of lakes which forced the armies to operate independently. After Russian victories at Stallupönen and Gumbinnen, a panicked Prittwitz ordered the abandonment of East Prussia and a retreat to the Vistula River. Stunned by this, Moltke sacked the Eighth Army commander and dispatched General Paul von Hindenburg to take command. To aid Hindenburg, the gifted General Erich Ludendorff was assigned as chief of staff. Battle of Tannenberg Before his replacement arrived, Prittwitz, correctly believing that the heavy losses sustained at Gumbinnen had temporarily halted Rennenkampf, began shifting forces south to block Samsonov. Arriving August 23, this move was endorsed by Hindenburg and Ludendorff. Three days later, the two learned that Rennenkampf was preparing to lay siege to Konigsberg and would be unable to support Samsonov. Moving to the attack, Hindenburg drew Samsonov in as he sent Eighth Army's troops in a bold double envelopment. On August 29, the arms of the German maneuver connected, surrounding the Russians. Trapped, over 92,000 Russians surrendered effectively destroying the Second Army. Rather than report the defeat, Samsonov took his own life. Battle of the Masurian Lakes With the defeat at Tannenberg, Rennenkampf was ordered to switch to the defensive and await the arrival of the Tenth Army which was forming to the south. The southern threat eliminated, Hindenburg shifted the Eight Army north and began attacking the First Army. In a series of battles beginning September 7, the Germans repeatedly attempted to encircle Rennenkampf's men, but were unable to as the Russian general conducted a fighting retreat back into Russia. On September 25, having reorganized and been reinforced by the Tenth Army, he launched a counter-offensive which drove the Germans back to the lines they occupied at the start of the campaign. Invasion of Serbia As the war began, Count Conrad von Hötzendorf, the Austrian Chief of Staff, vacillated over his nation's priorities. While Russia posed the greater threat, national hatred of Serbia for years of irritation and the assassination of Archduke Franz Ferdinand led him to commit the bulk of Austria-Hungary's strength to attacking their small neighbor to the south. It was Conrad's belief that Serbia could be quickly overrun so that all of Austria-Hungary's forces could be directed towards Russia. Attacking Serbia from the west through Bosnia, the Austrians encountered Vojvoda (Field Marshal) Radomir Putnik's army along the River Vardar. Over the next several days, General Oskar Potiorek's Austrian troops were repulsed at the Battles of Cer and Drina. Attacking into Bosnia on September 6, the Serbs advanced towards Sarajevo. These gains were temporary as Potiorek launched a counter-offensive on November 6 and culminating with the capture of Belgrade on December 2. Sensing that the Austrians had become overextended, Putnik attacked the next day and drove Potiorek out of Serbia and captured 76,000 enemy soldiers. The Battles for Galicia To the north, Russia and Austria-Hungary moved to contact along the border in Galicia. A 300-mile long front, Austria-Hungary's main line of defense was along the Carpathian Mountains and was anchored by the modernized fortresses at Lemberg (Lvov) and Przemysl. For the attack, the Russians deployed the Third, Fourth, Fifth, and Eighth Armies of General Nikolai Ivanov's South-Western Front. Due to Austrian confusion over their war priorities, they were slower to concentrate and were outnumbered by the enemy. On this front, Conrad planned to strengthen his left with the goal of encircling the Russian flank on the plains south of Warsaw. The Russians intended a similar encircling plan in western Galicia. Attacking at Krasnik on August 23, the Austrians met with success and by September 2 had also won a victory at Komarov (Map). In eastern Galicia, the Austrian Third Army, tasked with defending the area, elected to go on the offensive. Encountering the General Nikolai Ruzsky's Russian Third Army, it was badly mauled at Gnita Lipa. As the commanders shifted their focus to eastern Galicia, the Russians won a series of victories which shattered Conrad's forces in the area. Retreating to the River Dunajec, the Austrians lost Lemberg and Przemysl was besieged (Map). Battles for Warsaw With the Austrian's situation collapsing, they called upon the Germans for aid. To relieve pressure on the Galician front, Hindenburg, now the overall German commander in the east, pushed the newly formed Ninth Army forward against Warsaw. Reaching the Vistula River on October 9, he was halted by Ruzsky, now leading the Russian Northwest Front, and compelled to fall back (Map). The Russians next planned an offensive into Silesia, but were blocked when Hindenburg attempted another double envelopment. The resulting Battle of Lodz (November 11-23) saw the German operation fail and the Russians almost win a victory (Map). End of 1914 With the end of the year, any hopes for a swift conclusion to the conflict had been dashed. Germany's attempt to win a rapid victory in the west had been stymied at the First Battle of the Marne and an increasingly fortified front now extended from the English Channel to the Swiss border. In the east, the Germans succeeded in winning a stunning victory at Tannenberg, but the failures of their Austrian allies muted this triumph. As winter descended, both sides made preparations to resume large-scale operations in 1915 with the hope of finally achieving victory.