In terms of geopolitics, perhaps the most seminal event of the Middle Ages was the successful Ottoman siege of Constantinople in 1453. The city had been an imperial capital as far back as the 4th century, when Constantine the Great shifted the power center of the Roman Empire there, effectively establishing two almost equally powerful halves of antiquity's greatest empire. Constantinople would continue to serve as the capital of the Byzantine Empire even after the Western half of the Roman Empire collapsed in the late 5th century. Naturally, the Ottoman Empire would also use Constantinople as the capital of its empire after their conquest effectively ended the Byzantine Empire, and thanks to its strategic location, it has been a trading center for years and remains one today under the Turkish name of Istanbul.

The end of the Byzantine Empire had a profound effect not only on the Middle East but Europe as well. Constantinople had played a crucial part in the Crusades, and the fall of the Byzantines meant that the Ottomans now shared a border with Europe. The Islamic empire was viewed as a threat by the predominantly Christian continent to their west, and it took little time for different European nations to start clashing with the powerful Turks. In fact, the Ottomans would clash with Russians, Austrians, Venetians, Polish, and more before collapsing as a result of World War I, when they were part of the Central powers.

The Ottoman conquest of Constantinople also played a decisive role in fostering the Renaissance in Western Europe. The Byzantine Empire's influence had helped ensure that it was the custodian of various ancient texts, most notably from the ancient Greeks, and when Constantinople fell, Byzantine refugees flocked west to seek refuge in Europe. Those refugees brought books that helped spark an interest in antiquity that fueled the Italian Renaissance and essentially put an end to the Middle Ages altogether.

In the wake of taking Constantinople, the Ottoman Empire would spend the next few centuries expanding its size, power, and influence, bumping up against Eastern Europe and becoming one of the world's most important geopolitical players. It was a rise that would not truly start to wane until the 19th century, and the Ottomans would maintain their empire until the end of World War I.

Osman I, who is now recognized as being the first leader of the Ottoman Empire before dying in 1323 or 1324, is one of history's most important leaders, so it is ironic that little is known about his life. Historians have searched in vain for a single historical record dating from his reign, despite the fact he was the founder of the Ottoman Empire, a state which conquered Asia Minor, most of the Middle East, North Africa, and the Balkans before reaching the very walls of Vienna. In the struggle between Christian and Islamic powers, it was the first state to challenge hegemony over Europe since the Umayyad Caliphate was defeated by the Franks at the Battle of Tours in 732.

By the time of Suleiman's ascension, the Ottoman Empire was already in good condition. It was politically stable, culturally flourishing, dominating trade in the area, and in possession of a superior military organisation, which allowed Suleiman I to continue his predecessors' work without much need to change the direction of the empire. Selim's aggressive rule left the Janissaries efficient and strong, the Mamluks defeated, and the holy cities subsumed into the empire. The Republic of Venice in the west, as well as the Safavids in the east, had been weakened, and for the first time, the Ottoman had a fleet able to challenge old trade structures and rise as a new dominant power on the seas. Things were going well, and Suleiman intended to keep it that way.