The word ”Ottoman” is a historical  name of  Osman I (1258–1326), the founder of the Empire which was established in Turkey.  Osman I extended the frontiers of Turkish settlement toward the edge of the Byzantine Empire.

In the century after the death of Osman I, Ottoman rule began to extend over the Eastern Mediterranean and the Balkans. Osman’s son, Orhan, captured the northwestern Anatolian city of Bursa in 1324, and made it the new capital of the Ottoman state. This Ottoman conquest meant the loss of Byzantine control over northwestern Anatolia. The Ottoman victory at Battle of Kosovo in 1389 effectively marked the end of Serbian power in the region, paving the way for Ottoman expansion into Europe.

In the 15th century, the Ottoman Empire dramatically expanded the Empire’s eastern and southern frontiers by defeating Shah Ismail of Safavid dynasty in Persia, in the Battle of Chaldiran.  Sultan established rule in Egypt,and created a naval presence on the Red Sea. After this expansion, a competition started between the Portuguese Empire and the Ottoman Empire to become the dominant power in the region.  During the 16th and 17th centuries, at the height of its power, the Ottoman Empire was a multinational, multilingual empire controlling much of Southeast Europe, Western Asia, and North Africa.  At the beginning of the 17th century the empire contained as many as 32 Provinces  within the Ottoman Empire.

With  Istanbul as its capital and control of lands around the Mediterranean Sea basin, the Ottoman Empire was at the centre of interactions between the Eastern world and Western world worlds for six centuries. However, following a long period of Ottoman wars in Europe against European powers, the Ottoman Empire gradually declined into the late nineteenth century. In the twentieth century the empire allied with German Empire, with the imperial ambition of recovering its lost territories. While the Empire was able to largely hold its own during the World War I conflict, Ottoman was struggling with internal dissent, especially with the Arab Revolt in its Arabian holdings. Before and during  the World War I, Ottoman government committed genocides  against the Armenians and Greeks, killing between 100,000 and 300,000 Armenians living throughout the empire.  These genocides  eventually brought the dissolution of the Ottoman Empire.

The Arab Revolt which began in 1916 turned the tide against the Ottomans on the Middle Eastern front, where they initially seemed to have the upper hand during the first two years of the war.  The Empire’s defeat and the occupation of part of its territory by the World War I Allied Powers resulted in partitioning of Ottoman Empire with the emergence of a new state, Turkey, as well as the founding of modern Balkan and Middle Eastern states. The Armistice of Mudros was signed on 30 October 1918, and set the partition of the Ottoman Empire under the terms of the Treaty of Sèvres.  The Wahabi mission started as a revivalist movement in the remote, arid region of Najd. With the collapse of the Ottoman Empire, the Al Saud dynasty, and with it Wahabism, spread to the holy cities of Mecca and Medina. After the discovery of petroleum near the Persian Gulf in 1939, it had access to oil export revenues, revenue that grew to billions of dollars. This money – spent on books, media, schools, universities, and mosques,  – gave Wahabism a “preeminent position of strength” in Islam around the world.

(Source: “Shia Islam At A Glance”)