| A | B |
|---|
| Central Powers | In World War I, the nations of Germany and Austria-Hungary, along with the other nations that fought on their side. |
| Allied Powers | In World War I, the nations of Great Britain, France, and Russia, along with the other nations that fought on their side. |
| Western Front | In World War I, the region of northern France where the forces of the Allies and the central Powers battled each other. |
| Schlieffen Plan | Germany's military plan at the outbreak of World War I, according to which German troops would rapidly defeat France and then move east to attack Russia. |
| trench warfare | A form of warfare in which opposing armies fight each other from trenches dug in the battlefield. |
| Eastern Front | In World War I, the region along the German-Russian border where Russians and Serbs battled Germans, Austrians and Turks. |
| Sir Edward Grey | British foreign minister in 1914, famous for the comment that "The lamps are going out all over Europe. |
| First Battle of the Marne | A First World War battle fought between 5 and 12 September 1914. It resulted in an Allied victory againstthe German Army and effectively ended the month-long German offensive that opened the war and had reached the outskirts of Paris. |
| "no mans land" | A term that is most commonly associated with the First World War to describe the area of land between two enemy trenches that neither side wishes to openly move on or take control of due to fear of being attacked by the enemy in the process. |
| Battle of Verdun | One of the major battles during the First World War on the Western Front. It was fought between the German and French armies, from 21 February to 18 December 1916, on hilly terrain north of the city of Verdun-sur-Meuse in north-eastern France. |
| Battle of the Somme | A major battle fought during the First World War between 1 July and 18 November 1916 in the Somme department of France, on both banks of the river of the same name. One of the largest battles of the First World War, by the time fighting had ended in late autumn 1916 more than 1.5 million casualties had been suffered by the forces involved. It is understood to have been one of the bloodiest military operations ever recorded. |
| Battle of Tannenberg | A decisive engagement between the Russian Empire and the German Empire in the first days of World War I, fought by the Russian First and Second Armies and the German Eighth Army between 23 August and 30 August 1914. The battle resulted in the almost complete destruction of the Russian Second Army. |
| unrestricted submarine warfare | The use of submarines to sink without warning any ship (neutral or passenger liner) found in an enemy's waters. |
| total war | A conflict in which the participating countries devote all of their resources to the war effort. |
| rationing | The limiting of the amounts of goods people can buy - often imposed by governments during wartime, when goods are in short supply. |
| propaganda | Information or material spread to advance a cause or to damage an opponent's cause. |
| armistice | An arrangement to stop fighting. |
| Gallipoli Campaign | A series of battles that took place at Gallipoli peninsula in Turkey from 25 April 1915 to 9 January 1916, during the First World War. A joint British and French operation was mounted to capture the Ottoman capital of Istanbul, and secure a sea route to Russia. The attempt failed, with heavy casualties on both sides. |
| the Lusitania | an ocean liner owned by the Cunard Line, she was torpedoed by the SM U-20, a German U-boat on 7 May 1915 and sank in eighteen minutes, eight miles off the Old Head of Kinsale, Ireland, killing 1,198 of the 1,959 people aboard. The sinking turned public opinion in many countries against Germany. |
| Zimmerman Note | A coded telegram to the German ambassador in Washington at the height of World War I and forwarded to the German ambassador in Mexico. it offered German assistance to Mexico if the United States entered the war on the Allied side. |
| Treaty of Brest-Litovsk | A peace treaty signed on March 3, 1918, at Brest-Litovsk between the Soviet Russian and the Central Powers, marking Russia's exit from World War I. |
| Second Battle of the Marne | The last major German Spring Offensive on the Western Front during World War I. It failed when an Allied counterattack led by French forces overwhelmed the Germans, inflicting severe casualties. |
