World War I broke in the Balkans as a direct result of the assassination of the Austro-Hungarian Crown Prince Franz Ferdinand in Sarajevo. Austria-Hungary, with the backing of Germany and the Ottoman Empire (alliance known as "The Central Powers") attacked Serbia who received the support of the Entente (the British Empire, France, Russia, Italy.) The Central Powers were able to engage as an ally the country with the largest army in the region - Bulgaria. Its entry in the war meant a death blow to Serbia and Romania and ensured the continuous Ottoman war effort by opening the way for much needed German material assistance. Initially the war was characterized with highly successful campaigns of rapid movements in 1915 and 1916. However, once most Bulgarian territorial aspirations had been satisfied it degraded into a state of trench attrition. This prolonged period substantially weakened the economy, created various supply problems and reduced the health and morale of the troops on the front lines. Under these circumstances the Allied armies in Greece, composed of contingents from almost all Entente countries, managed to break the Macedonian Front and cause the rapid collapse of part of the Bulgarian Army. Bulgaria was forced to seek and accept an armistice on 30 September 1918.
The campaign in the Balkans is represented below by two maps from the Olin Library map collection, and maps and images in the public domain, downloaded from Wikimedia Commons.Click image to enlarge.
The Middle Eastern theater of World War I was the scene of action between 29 October 1914, and 30 October 1918. The combatants were on the one hand, the Ottoman Empire with some assistance from the other Central Powers and local tribal groups (Kurds, Turcomans, Circassians, Chechens and a number of Iranian, Arab and Berber tribes); and on the other hand, the British and the Russians (with the aid of the Armenians, Assyrians, Jews and the majority of Arabs.) There were five main campaigns: the Sinai and Palestine Campaign, the Mesopotamian Campaign, the Caucasus Campaign, the Persian Campaign, and the Gallipoli Campaign. Significant Turkish forces were sent into the Russian Caucasus, where they were annihilated in the snowbound mountains. However, in April 1915 the Ottoman army prevented the British seizure of Gallipoli and the Dardanelles. More British disasters followed. A small Anglo-Indian force advanced in Mesopotamia, but was besieged and forced to surrender in April 1916. An Ottoman attack on the Suez Canal was repulsed by British forces, but the effort to dislodge the Turks from Sinai was unsuccessful until 1917 when Gen. Allenby took Jerusalem. In Persia there were a series of engagements between the British Empire, Russian Empire and Armenian and Assyrian forces against the Ottoman Empire, beginning in December 1914 and ending with the Armistice of Mudros on October 30, 1918. The Russian operations were halted by the Russian Revolution on February 23, 1917 when the Russian Caucasus Army was replaced with Armenian units and an Allied force named Dunsterforce. By September 1918, the Ottomans consolidated their control over northern Persia, but they lost the rest of the region to British. On 30 October 1918, the Ottoman Empire signed the Armistice of Mudros and the military operations ended. The British occupied the territory that was to become Iraq, Palestine, Trans-Jordan, Syria and Lebanon.
The Olin Library Maps Department staff generated the following map of the Middle East operations and the chart with casualties. Data was compiled from R. Grey's "Chronicle of the First World War."Click image to enlarge.