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.
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.
Among those who were responsible for the projection of Ottoman power, few deserve as much credit as the Janissaries. Established by Murad I, the Janissaries became an elite infantry force that was loyal only to the sultan. Their mission was to protect only him and in battles they were always the closest to him, forming a human shield.
Civilizations across the steppes and the Middle East relied heavily on cavalry, and the Sipahi were elite cavalry units during medieval times for a couple of powers. That said, they were a massive contributor to the success of Ottoman warfare, and during good times for the empire, the Sipahi were rewarded, to the extent that they became their own social class, much like the Janissaries.
