The Central Powers, also known as the Central Empires, were one of the two main coalitions that fought in World War I (1914–1918). It consisted of the German Empire, Austria-Hungary, the Ottoman Empire, and Bulgaria; this was also known as the Quadruple Alliance.
The Western Front was one of the main theatres of war during the First World War. Following the outbreak of war in August 1914, the German Army opened the Western Front by invading Luxembourg and Belgium, then gaining military control of important industrial regions in France. The German advance was halted with the Battle of the Marne. Following the Race to the Sea, both sides dug in along a meandering line of fortified trenches, stretching from the North Sea to the Swiss frontier with France, the position of which changed little except during early 1917 and again in 1918.
The Schlieffen Plan is a name given after the First World War to German war plans, due to the influence of Field Marshal Alfred von Schlieffen and his thinking on an invasion of France and Belgium, which began on 4 August 1914. Schlieffen was Chief of the General Staff of the German Army from 1891 to 1906. In 1905 and 1906, Schlieffen devised an army deployment plan for a decisive (war-winning) offensive against the French Third Republic. German forces were to invade France through the Netherlands and Belgium rather than across the common border.
The European theatre of World War II was one of the two main theatres of combat during World War II. It saw heavy fighting across Europe for almost six years, starting with Germany's invasion of Poland on 1 September 1939 and ending with the Western Allies conquering most of Western Europe, the Soviet Union conquering most of Eastern Europe including the German capital Berlin, and Germany's unconditional surrender on 8 May 1945 although fighting continued elsewhere in Europe until 25 May. On 5 June 1945, the Berlin Declaration proclaiming the unconditional surrender of Germany to the four victorious powers was signed. The Allied powers fought the Axis powers on two major fronts, but there were other fronts varying in scale from the Italian campaign, to the Polish Campaign, as well as in a strategic bombing offensive and in the adjoining Mediterranean and Middle East theatre.
The Eastern Front or Eastern Theater of World War I was a theater of operations that encompassed at its greatest extent the entire frontier between Russia and Romania on one side and Austria-Hungary, Bulgaria, the Ottoman Empire, and Germany on the other. It ranged from the Baltic Sea in the north to the Black Sea in the south, involved most of Eastern Europe, and stretched deep into Central Europe. The term contrasts with the Western Front, which was being fought in Belgium and France.
The Austro-Hungarian Navy or Imperial and Royal War Navy was the naval force of Austria-Hungary. Ships of the Austro-Hungarian Navy were designated SMS, for Seiner Majestät Schiff. The k.u.k. Kriegsmarine came into being after the formation of Austria-Hungary in 1867, and ceased to exist in 1918 upon the Empire's defeat and subsequent collapse at the end of World War I.
The Second Battle of the Piave River, fought between 15 and 23 June 1918, was a decisive victory for the Italian Army against the Austro-Hungarian Empire during World War I, as Italy was part of the Allied Forces, while Austria-Hungary was part of the Central Powers. Though the battle proved to be a decisive blow to the Austro-Hungarian Empire and by extension the Central Powers, its full significance was not initially appreciated in Italy. Yet Erich Ludendorff, on hearing the news, is reported to have said he 'had the sensation of defeat for the first time'. It would later become clear that the battle was in fact the beginning of the end of the Austro-Hungarian Empire.
According to military terminology, a two-front war occurs when opposing forces encounter on two geographically separate fronts. The forces of two or more allied parties usually simultaneously engage an opponent in order to increase their chances of success. The opponent consequently encounters severe logistic difficulties, as they are forced to divide and disperse their troops, defend an extended front line, and is at least partly cut off from their access to trade and exterior resources. However, by virtue of the central position, they might possess the advantages of the interior lines.
The Entente, or the Allies, were an international military coalition of countries led by France, the United Kingdom, Russia, the United States, Italy, and Japan against the Central Powers of Germany, Austria-Hungary, the Ottoman Empire, and Bulgaria in World War I (1914–1918).
The Balkans theatre or Balkan campaign was a theatre of World War I fought between the Central Powers and the Allies.
World War I or the First World War was a global conflict between two coalitions: the Allies and the Central Powers. Fighting took place throughout Europe, the Middle East, Africa, the Pacific, and parts of Asia. One of the deadliest wars in history, it resulted in an estimated 9 million soldiers dead and 23 million wounded, plus up to 8 million civilian deaths from numerous causes including genocide. The movement of large numbers of troops and civilians during the war was a major factor in spreading the 1918 Spanish flu pandemic.
The Kingdom of Romania was neutral for the first two years of World War I, entering on the side of the Allied powers from 27 August 1916 until Central Power occupation led to the Treaty of Bucharest in May 1918, before reentering the war on 10 November 1918. It had the most significant oil fields in Europe, and Germany eagerly bought its petroleum, as well as food exports.
Naval warfare in the Mediterranean during World War I took place between the naval forces of the Entente and the Central Powers in the Mediterranean Sea between 1914 and 1918.
The Macedonian front, also known as the Salonica front, was a military theatre of World War I formed as a result of an attempt by the Allied Powers to aid Serbia, in the autumn of 1915, against the combined attack of Germany, Austria-Hungary and Bulgaria. The expedition came too late and with insufficient force to prevent the fall of Serbia and was complicated by the internal political crisis in Greece. Eventually, a stable front was established, running from the Albanian Adriatic coast to the Struma River, pitting a multinational Allied force against the Bulgarian army, which was at various times bolstered with smaller units from the other Central Powers. The Macedonian front remained stable, despite local actions, until the Allied offensive in September 1918 resulted in Bulgaria capitulating and the liberation of Serbia.
Although a member of the Triple Alliance, Italy did not join the Central Powers – Germany and Austria-Hungary – when the war started with Austria-Hungary's declaration of war on Serbia on 28 July 1914. In fact, the two Central Powers had taken the offensive while the Triple Alliance was supposed to be a defensive alliance. Moreover the Triple Alliance recognized that both Italy and Austria-Hungary were interested in the Balkans and required both to consult each other before changing the status quo and to provide compensation for whatever advantage in that area: Austria-Hungary did consult Germany but not Italy before issuing the ultimatum to Serbia, and refused any compensation before the end of the war.
The following outline is provided as an overview of and topical guide to World War I:
At the outbreak of World War I in August 1914, Hungary was part of the Dual Monarchy of Austria-Hungary. Although there are no significant battles specifically connected to Hungarian regiments, the troops suffered high losses throughout the war as the Empire suffered defeat after defeat. The result was the breakup of the Empire and eventually, Hungary suffered severe territorial losses by the closing Trianon Peace Treaty.
The Liberation of Serbia, Albania and Montenegro was a military action in the Balkans in the final weeks of World War I. Between 29 September and 11 November 1918, the Allied Army of the Orient liberated these three countries from occupation by the Central Powers.
The following is a timeline of the events of World War I from 1917 to 1918.
German Empire 
Austria-Hungary 
Bulgaria 
Ottoman Empire 
Russian SFSR 
