The next few centuries were marked by a period of expansion. The boundaries of the Empire spread from eastern Anatolia to encompass the Balkans and the Eastern Mediterranean, including much of the lands of the weakened Byzantine Empire. In fact, at its height under Suleiman the Magnificent, the territorial holdings of the Ottoman Empire mirrored those of the Byzantines at their apogy under Justinian the Great nearly a millennium prior. However, it was not until 1453 that the Ottomans finally captured Constantinople after a long siege, renaming it Istanbul and establishing their capital there. While Ottoman military power was due in large part to the famed Janissary soldiers who were originally drawn from prisoners of war and slaves and later from mostly Christian youths, their economic might was derived in large part from their control of trade routes linking the Middle East with the West.

Over time, the Empire began to stagnate as a series of weak Sultans were unable to compete with the military and scientific advances revolutionizing the West. The discovery of the New World and the opening up of maritime trade routes between Europe and the Americas, India, and the Far East diluted the economic might of the Ottomans. A series of failed reforms were unable to reverse the decline, resulting in huge losses of territory on all fronts. The rise of nationalism during the 19th century further exacerbated this problem as numerous ethnically distinct provinces declared their independence and the Turks themselves began to clamor for reform. To some degree, during the late stages, the Ottoman Empire was propped up by European powers such as Britain and France as a bulwark against Russian expansion towards the Eastern Mediterranean. World War I effectively resulted in the end of the empire as the remaining territory of defeated Ottomans was partitioned by the Allies. The Turkish War of Independence erupted in 1919, culminating with the abolition of the Sultinate in 1922 and the declaration of the modern Republic of Turkey in 1923.