The conflict's trigger is usually considered to be the assassination on 28 June 1914 of Archduke Franz Ferdinand of Austria, the heir to the Austro-Hungarian throne. Other causes, such as imperialistic foreign policy and the development of complex military alliances, also helped turn a would-be minor conflict into a larger one. Ferdinand's assassination at the hands of Yugoslav nationalist Gavrilo Princip resulted in Habsburg ultimatum against the Kingdom of Serbia. The military alliances that had been drawn up among the imperial nations were quickly invoked, resulted a continental war among the European powers.
Course of the War
By the end of August 1914, all declarations of war until the end of the conflict had been invoked. The war's first major action was the invasion of Belgium and Luxembourg by the German Empire, as part of their Schlieffen plan. Although many British politicians demanded war with Germany in defense of Belgium's neutrality, the declaration was narrowly defeated in Parliament and Britain remained neutral. Although much resistance was put up by the Belgians, the Germans were advancing into French territory before the month ended. France, surprised by the offensive, was unable to move their troops in time, who were focused on recapturing Alsace-Lorraine, a mixed French-German territory that had switched allegiances previously.
On September 16, the Germans had surrounded Paris and were moving in to capture the city. Two days later, France sued for peace. Belgium quickly signed an indefinite ceasefire with the Central Powers. A treaty was signed later in the month, where France had to give up their colony of Tunisia to Italy (promised in exchange for neutrality earlier in the war), small parts of French West Africa to Austria-Hungary, and other parts of French West Africa to Germany. Belgium received a white peace.
Imperial Russia took time to mobilize for the unexpected war, but were still faster than expected to mobilize. By September, much of the Russian army was beginning their offensives against Austria-Hungary and Germany. Russian forces were able to make gains into German and Austro-Hungarian territory by the end of September.
However, with the surrender of France, the Central Powers, along with Bulgaria, who had recently joined the war, were able to reverse their losses by mid October. After pushing the fronts into Russian territory by October 16, the war settled into a stalemate until November 9, when a large offensive began led by the three anti-Russian allies. This broke through the Russian lines, and made considerable gains daily. Weakened by the approaching winter, the gains began to shrink by December, but by that time it was too late. A victory at Smolensk was achieved on December 14, and the next day, Russia surrendered. A treaty was later signed, which gave small amounts of Russian territory to Romania, Austria-Hungary, and Germany. Germany received the territory it had ceded to Russia in 1815, and Romania received Bessarabia.
Austria-Hungary made the first action of the entire conflict by invading Serbia on July 28. Montenegro declared war on August 2, in defense of their allies, Serbia and Russia. Belgrade was captured on August 25, after slow advances due to resistance and guerrilla tactics by the defending forces. However, following the capture of the city, Austria-Hungary was able to coax Bulgaria into joining the war on their side, with the official declaration of war occurring on August 29.
Bolstered by the Bulgarian forces, the invasion began to move fairly quickly, despite determined defending forces. When the Russians largely withdrew so that they could defend their own territory from Germany after the surrender of France, the two Balkan nations jointly surrendered on October 22. They were later annexed into Bulgaria and Austria-Hungary. However, this was not to last, as the collapse of Austria-Hungary occurred just two and half years later, in 1917.
The aftermath of the conflict helped set up Europe for another war, in several ways. The balance of power had been changed: Germany had proved its strength and forced France and Russia to give up small amounts of territory in peace. It also pushed several nations onto the side of the Central Powers, such as the now re-aligned Italy, secretly nullifying its also secret pact with France, creating an interesting web of phony treaties. Economically, the war created significant amounts of debt for the warring nations, though most of the nations did not have much trouble paying the debt off. The war also ramped up technological advances, mainly of superheavy war machines, like tanks. The most notable effect of the new technology was the lack of trench warfare. In the 1914 Incident, trenches were only established for small amounts of time, and only on the Eastern Front. Trenches were locked out of entering history with the new offensive technology to complement the defensive advances.
Politically, the quick victory of the Central Powers over the Triple Entente helped push the allegiance of several nations over to the Central Powers, who were viewed as a more powerful group of nations after the war. Greece, Romania, Bulgaria, and the Ottoman Empire all began warming up to the Central Powers, signing trade and military agreements with Austria-Hungary, Germany, and Italy. The seven nations later come into play in the following military conflicts. Albania would officially remain a neutral state, but had been guaranteed protection by both former Entente and Central Powers nations. The war also lead to the great instability of Austria-Hungary after the death of Franz Joseph in 1916, and eventually collapse.
In the final treaty that ended the war, the Treaty of Amsterdam, the Triple Entente was de jure dissolved. However, France and Russia established an alliance in August 1915, and were later joined by many Slavic slates under the influence of Russia.
Most of the prestige in Germany for the quick victory in the war transferred from the monarchy of Wilhelm II, who was growing slowly more unpopular, to the military. With the weakening of Prussia after Austria joined the German Empire in 1917, and the push for democratic reforms was eventually met in 1920s, though Wilhelm II remained emperor until his death in 1940. As he grew older, he became wiser (along with becoming less powerful), and allowed German diplomats to attempt to reconcile with other nations, such as France or Russia instead of remaining at odds with them.
Angered by the war, poorer Russian peasants and industrial workers began to protest against the government and richer citizens. The protests began on March 29, 1915. The government at first made some small concessions, but protests continued. In response, the government began to crack down on the protests. Vast members members of the police and military refused to fire on the protesters in solidarity with them. On May 12, 1915, the government began reform processes. Taxes were raised on richer people, more civil rights respected, and elections, to be held later than year, were made more fair, placating the protesters. The failure of the government to put down the protests was seen as an uproar in other countries. However, the trust of the Russian people in their government was beginning to increase, and this also eventually would lead to further democratic reforms in Russia. The protests and reforms would come to be known as the 1915 Revolution.