The Ottoman Empire (Turkey) was one of the countries engaged in the First World War, 1914-1918, allied with Austria/Hungary and Germany. Like Austria/Hungary and Germany, the Ottoman Empire was broken up, with many parts becoming plebecites and even whole new nations. The following paragraphs discuss how the Ottoman Empire was broken down into the modern Middle-Eastern countries we know today.
During most of the 19th century, the Ottoman Empire stretched from Egypt to the borders of Persia, from what today is Bosnia and Macedonia almost to the Port of Aden on the southern edge of the Arabian Peninsula. The Ottoman Empire was the remnants of the original domain of Saladin and the caliphates of Constantinople at the height of the Muslim expansion. It has included such territories as Epirus and Crete, Cyprus, Egypt and Sudan, a significant part of North Africa, and the Arabian Peninsula, during some portion of its existence. Today, it's best represented by Turkey, the central portion of the Ottoman Empire, and the home of the Empire's capital, Constantinople, now Istanbul. It covers the "hinge" between Europe, Asia, and Africa, and has included bits and pieces of all three continents at one time or another.
At its height, the Ottoman Empire was the pre-eminent force in the Mediterranean, with territories that stretched from Tunisia to Persia. The Ottoman Empire gradually declined, however, and by the 1800s was a weak but huge association of interlocking political, religious, and economic units that otherwise were at least semi-autonomous, if not totally so. Since the Ottoman Empire wrapped around the eastern end of the Mediterranean, it was of great interest to the European powers of the day, which included England, France, and Russia. The European nations managed to engage the Ottoman Empire in many of the wars and skirmishes that occupied that part of the world, beginning with the Napoleanic wars, and culminating with World War I and its aftermath. During each of these various European infringements, the Ottoman Empire lost more territory. The Caliphate of Egypt was the first pried loose from the Ottoman Empire, ostensibly as an independent caliphate, but in practice, first a French, then British, vassal. Other territorial losses in Africa included Tunisia (in 1880, to France), and Libya (in 1912, to Italy).
Much of the Ottoman Empire's European portions were lost between 1830 and 1914. During that time, Russia attempted to gain access to the Mediterranean through Ottoman territory, and Britain and France fought to prevent it. The Ottoman Empire had grown relatively weak, and Russia had considered it an easy target. The corruption of the Ottoman Empire was well-known, as was the political in-fighting that was rampant, and which had led to the loss of Egypt to Muhammad Ali by 1839. Additional wars involving France, Britain, Russia, and the Ottoman Empire resulted in the loss of Crete, Cyprus, large portions of what is now Greece, Bosnia & Herzegovina, Montenegro, Albania, Bulgaria, and portions of what is now Romania between 1840 and 1913. The Ottoman Empire joined Germany and Austria-Hungary against Russia, Great Britain, Italy, and France during World War I. Following the end of the war, the Ottoman Empire lost most of its territory except for what is today modern Turkey, and a few bits and pieces that had been given plebiscites to determine what nation they would align themselves with.
