Opening hostilitiesConfusion between the Central PowersThe Central Power’s plan was effected greatly with mis-communication. Germany made promise with Austria-Hungary’s to support its intrusion of Serbia, but perception of what this meant differed greatly. Previously tested plans for deployment were replaced earlier in 1914, but they were not yet tested in real life. Austro-Hungarian thought their northern side would be protected by Germans from Russia. Germans, whereas, believed Austria-Hungary would automatically send most of its army against Russia, in the meantime Germans will take care of France. This ultimately led to the Austria-Hungary to divide its army forces between the Serbia and Russia’s front.Serbian campaignAustria invaded the Serbia and fought with its army the Battles of Cer and Kolubara on 12th of August. But in the coming week Austrian suffered with great loss, which resulted in the marking of the first big Allied victories of the war and crushed the hopes of Austria-Hungary of an easy defeat of Serbia. Thus, Austria kept proper amount of forces over the Serbian side, as a result its struggle against Russia wakened. And this victory of Serbia’s against the Austro-Hungarian intrusion in 1914 has been known as one of the major upset victories of 20th century.German forces in Belgium and FranceAs the occurrence of WWI happened, approximately 80% of the total army of Germany was deployed as 7 field armies on west front according to the plan called Aufmarsch II West. But later on, these were reassigned to follow the deployment plan known as Schlieffen Plan, sometimes referred to as the Aufmarsch I West. According to this strategy Germans will march through the north of Belgium and then into the France, in an attempt to surround the army of France and then enter the fortresses of Verdun’s second defensive area then the Paris and then the river Marne.Aufmarsch I West was the one convenient to the Germans out of the 4 total deployment plans at the time. Each plan had certain advantageous output, but they had no idea how to actually execute any one of these plans, resulting in commanding officers carrying them out as their own initiative, with minimum omission. Plan Aufmarsch I West, was designed in a way to have one-front war with the French army, after trying it once it eventually became clear that in the end it was irrelevant to the wars, Germany could expect to face; Russia and Britain both of them were expected to help out the French army, whereas there was zero possibility of availability of troops of Italy or Austria-Hungary for operations adjacent to France. But ultimately it was able to retain a certain charm due to its nature and the pessimism of pre-war thinking. Thus, for the offensive of 1914, the Aufmarsch II West deployment was changed. Moltke observed Schlieffen’s plan, changing the deployment of the army on western side by decreasing the wing from 85% to 70% the one that had to enter through the Belgium. At last, the Schlieffen plan was drastically changed by Moltke, thus it was also called as the Moltke Plan.The plan called for the right wing of Germans to move to bypass the armies of France concentrated on France-German border, then defeating the France forces near the Luxembourg and Belgium and afterwards moving towards south to the Paris. Initially the Germans got victory, especially in the battle of frontiers. But towards the 12 of September, the French army with the help of Britain force stopped the Germans entry into the east side of Paris and forced the Germans back to almost approximately 50km.On the eastern side, Russia entered with 2 armies. As a result, Germans moved the 8th Field Army to Eastern Russia. This troop of army, which was led by General Paul von Hindenburg, defeated the Russia in a combination of battles called the First Battle of Tannenberg (17 August – 2 September). Whereas the Russian intrusion failed, it resulted in movement of Germans army towards the eastern side… Thus Germans were unable to achieve their objective of avoiding a long, 2 front war. But, the Germans were able to fight its way into a good position inside of the France and were able to lower France’s coal supply to half. It was also responsible for crippling of somewhat 230,000 or more French and British army men than it has lost itself. More so ever, communication problems and decisions made by leaders costed Germany the chance of a more of a different kind of an outcome.Asia and the PacificOn 28th of October, the German cruiser sank down the Russian cruiser at the Battle of Penang. Japan stopped Germany’s Micronesian colonies and, after the Siege of Tsingtao. As Vienna refused to take out the Austro-Hungarian cruiser SMS, Japan declared war not only on Germany, but also on Austria-Hungary. Within a few months, the Allied forces had stopped all the German territories in the Pacific.African campaignsSome of the first conflict of the war was between British, French, and German colonial forces in Africa. On 6–7 August, French and British army entered the German colonies. On 10th August, Germans in South-West Africa attacked on the South Africa; brutal fighting lasted for the rest of the war. The German colonial forces which were led by Colonel Paul von Lettow-Vorbeck, fought with guerrilla warfare campaign during World War I and ultimately surrendered after two weeks.Indian support for the AlliesGermans tried to use Indians and Muslims for their own advantage, by sending a mission that urged Afghans to join the war alongside Central powers. But, as opposed to British fears of a revolt in subcontinent, this outbreak saw an unexpected sense of loyalty and goodwill towards Britain. Political leaders from the Congress and other groups were happy to support the Britain, because they believed that their support would further the cause of Indians Home Rule. The failure of the Britain government to allow self-government to India, caused starting of disillusionment and fueled the campaign for full independence led by Gandhi and the other.Western FrontTrench war startsStrategies used by army before WWI wasn’t enough at all for keeping the pace required with the everyday advancement in technology. This pushed them to try creating a strong defensive systems. Barbed wire, artillery coupled with machine guns, were used for making crossing on no mans land very difficult. By the passage of time technology was able to make new weapons including chlorine gas and tanks.Now both armies tried to cross on another as they moved to the north side this is also known as the “Race to the Sea”. But these efforts didn’t succeeded and forces came to realize that continuous line of trenches was formed extending from Lorraine to Belgium’s coast. Trenches made by Germans were much better made then their opponents.Chlorine gas was used firstly at Western Front by Germans but late it was used by french as well. Tanks were firstly used by British and French armies in great numbers, whilst the Germans used very small number by taking their tanks and changing it for their own use.Neither side proved to be able to deliver a decisive blow for the coming 2 years. The British Empire and French suffered more deaths than Germans did. Sometimes Germans advanced a little sometimes french made the advancement with no big change of territory for both sides. But at this time all three of the armies faced new challenges and tried evolving with every new challenge they faced along the way.Naval warAt the beginning, German cruisers were dispersed around the world. But Britain Navy strategically destroyed some of them down. Britain started blocking naval routes cutting down all kinds of supplies of Germans. The Jutland battle is one of the biggest naval battle of the WW1. Britain fleets tried damaging the German boats but in return got more attacked as a result.Germans  tried to block the supply routes from North America to Britain. But after the Protestantism of United States, Germans made promise that they wont attack passenger anymore.Threat of Germans U boats lessened after 1916 when new technology such as hydrophone as well as depth charges were produced, and by using these submarines were submerged or sank down in waters. The U-boats destroyed almost 5,000 ships of allied countries, by using their almost 198 submarines.Southern theatresWar in the BalkansDue to fighting with Russia at same time, Austria-Hungary was able to give only one third of the army for performing the attack on Serbia. They entered Siberia but after a few time of staying, Siberia was able to kick them out of their country. In the initial 10 months of 1915 Austria-Hungary utilized almost more than half of their military resources to attack Italy. Central powers persuaded Bulgaria to join and attack Siberia. Bulgaria announced war with Serbia, and joined the Austro-Hungarian army. Serbia was defeated in approximately 1 month. After wining, Serbia was divided among them.Now, the Macedonian side was almost abandoned. France and Serbia together retook small areas of Serbia back. And in September of 1918 they finally made a progress, after most of the Germans and Austro-Hungarian army were gone. The Bulgaria was defeated on 25th of September 1918. Germans tried to help but it was too late. And after a day of collapsing Bulgaria started seeking for an immediate peace settlement.Ottoman EmpireAs war progressed, Empire of Ottoman gained advantage of Europe’s war and and joined Central power. In Gallipoli, the Ottoman strategically answer attacked the Australia, France, Britain and New Zealand’s Army Corps also called AZNACS. In Mesopotamia, Britains took Baghdad in March. In August along with Germans they were defeated at the Battle of Romani by the ANZAC. Afterwards, an Egyptian Expeditionary Force advanced across the Sinai Peninsula in January 1917. Enver Pasha went against the Russians in 1914 and losing almost 87% of his force at the Battle of Sarikamish.The Ottomans, with Germans support, invaded Persia in December 1914 in order to cut off Britain and Russia access to petrol reservoirs. They were also helped by Kurdish and Azeri forces, together with many tribes from of Iran. the Russian withdrew from war in 1917. General Yudenich pushed Turks out of Caucasus. The Arab Revolt started June 1916, led by Sherif Hussein, leading to the surrender of Damascus by Ottoman. Approximated casualties of Ottoman were 725,000.Italian participationOn 23rd of May Italy announced war on Austria-Hungary. After some time, Italy also announced war on Germany. The Italians were superior in terms of number but due to fighting in the difficult terrain they were at loss, also strategies used by them proved to be very poor.Afterwards the Italians mounted eleven attacks on the Isonzo. All eleven attacks were withstood by the Austro-Hungarians.On 26th of October 1917 Central Powers started an attack achieving victory at Caporetto. The Italian Army was pushed back almost a hundred kilometers. In 1918, the Austria-Hungary didn’t succeed in breaking through a series of battles on the Piave and then were ultimately badly defeated in Vittorio Veneto battle. Austria-Hungary surrendered on 11 November 1918.Romanian participation At beginning of war, Romania announced its neutrality. In August 1916, Romanians attacked Austria-Hungary, with support from Russia. It was successful at first, but an attack by the Central Powers pushed Romanians back whilst occuping Bucharest. Fighting in Moldova continued in 1917. Russian withdrew from the war forcing the Romanians to sign an treaty with Central Powers on 9th of December.Peace treaty was made between Romanians and the Central Powers. Under that treaty, Romania had to stop the war with Central Powers and give some of the land to Austria-Hungary. The estimated deaths of Romanians during this period were approximately 748,000.