The Rise of the Turks and the Ottoman Empire
The restored Byzantine Empire was surrounded by enemies. The Bulgarian Empire, which had rebelled against the Byzantines centuries earlier, now matched it in strength. A new empire arose in the western Balkans, the Serbian Empire, who conquered many Byzantine lands. Even more dangerous to the Byzantines, the Turks were once again raiding Byzantine lands, and Asia Minor was overrun. With the theme system a thing of the past, the emperors had to rely on foreign mercenaries to supply troops, but these soldiers-for-hire were not always reliable. Anatolia gradually transformed from a Byzantine Christian land into an Islamic land dominated by the Turks.
For a long time the Turks in Anatolia were divided up into a patchwork of small Islamic states. However, one ruler, Osman I, built up a powerful kingdom that soon absorbed all the others and formed the Ottoman 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 city of Bursa in 1324 and made it the new capital of the Ottoman state. The fall of Bursa meant the loss of Byzantine control over Northwestern Anatolia. The important city of Thessaloniki was captured from the Venetians in 1387. The Ottoman victory at Kosovo in 1389 effectively marked the end of Serbian power in the region, paving the way for Ottoman expansion into Europe. The Battle of Nicopolis in 1396, widely regarded as the last large-scale crusade of the Middle Ages, failed to stop the advance of the victorious Ottoman Turks. With the extension of Turkish dominion into the Balkans, the strategic conquest of Constantinople became a crucial objective.
The Empire controlled nearly all former Byzantine lands surrounding the city, but the Byzantines were temporarily relieved when Timur invaded Anatolia in the Battle of Ankara in 1402. He took Sultan Bayezid I as a prisoner. The capture of Bayezid I threw the Turks into disorder. The state fell into a civil war that lasted from 1402 to 1413, as Bayezid's sons fought over succession. It ended when Mehmed I emerged as the sultan and restored Ottoman power.
When Mehmed I's grandson, Mehmed II (also known as Mehmed the Conquerer) ascended to the throne in 1451 he devoted himself to strengthening the Ottoman navy and made preparations for the taking of Constantinople.
Byzantium Looks West for Aid
Against all these enemies, the Byzantines could only look west in search of help. The pope, however, continued to stress that aid would only come if the Byzantines adopted the Catholicism of the Latin Church. While the Byzantine emperors were willing to do so in order to save their empire, the populace hated the Catholics for the sack of Constantinople, and so attempts to reconcile with the Catholic Church only led to riots. Further theological disagreements inflamed the bitterness between the Orthodox and the Catholics.
While civil war and religious disputes occupied the Byzantines, the Ottomans slowly closed in on the empire. They crossed into Europe and annexed most of the lands around Constantinople. By 1400 CE, the Byzantine Empire was little more than the city-state of Constantinople. It was clear that the only way they would receive Europe-wide help in pushing back the Ottomans was if they reconciled with the Catholic Church.
This was not acceptable for most Byzantines. A popular saying at the time was "Better the Turkish turban than the Papal tiara." In other words, the Orthodox Byzantines considered it better to be ruled by the Muslim Turks than to go against their religious beliefs and give in to the Catholic Church. Still, the emperors realized that Byzantium would soon fall without help from the West.
In 1439 CE, Emperor John VIII Palaiologos and the most important Byzantine bishops reached an agreement with the Catholic Church at the Council of Florence in which they accepted Catholic Christianity. When the bishops returned to the Byzantine Empire, however, they found themselves under attack by their congregations. Their agreement to join the Catholic Church was exceedingly unpopular.
The Rise of the Ottoman Empire
The borders of the Byzantine and Ottoman Empires in the Eastern Mediterranean just before the fall of Constantinople in 1453 CE.
The Fall of Constantinople
Constantinople by this stage was underpopulated and dilapidated. The population of the city had collapsed so severely that it was now little more than a cluster of villages separated by fields. On 2 April 1453, the Ottoman army, led by the 21-year-old Sultan Mehmed II, laid siege to the city with 80,000 men. Despite a desperate last-ditch defense of the city by the massively outnumbered Christian forces (7,000 men, 2,000 of whom were sent by Rome), Constantinople finally fell to the Ottomans after a two-month siege on 29 May 1453. The last Byzantine emperor, Constantine XI Palaiologos, was last seen casting off his imperial regalia and throwing himself into hand-to-hand combat after the walls of the city were taken.
On the third day of the conquest, Mehmed II ordered all looting to stop and sent his troops back outside the city walls. Byzantine historian George Sphrantzes, an eyewitness to the fall of Constantinople, described the Sultan's actions:
On the third day after the fall of our city, the Sultan celebrated his victory with a great, joyful triumph. He issued a proclamation: the citizens of all ages who had managed to escape detection were to leave their hiding places throughout the city and come out into the open, as they to were to remain free and no question would be asked. He further declared the restoration of houses and property to those who had abandoned our city before the siege, if they returned home, they would be treated according to their rank and religion, as if nothing had changed.
The capture of Constantinople (and two other Byzantine splinter territories soon thereafter) marked the end of the Roman Empire, an imperial state that had lasted for nearly 1,500 years. The Ottoman conquest of Constantinople also dealt a massive blow to Christendom, as the Islamic Ottoman armies thereafter were left unchecked to advance into Europe without an adversary to their rear. After the conquest, Sultan Mehmed II transferred the capital of the Ottoman Empire from Edirne to Constantinople. Constantinople was transformed into an Islamic city: the Hagia Sophia became a mosque, and the city eventually became known as Istanbul.
The conquest of the city of Constantinople and the end of the Byzantine Empire was a key event in the Late Middle Ages, which also marks, for some historians, the end of the Middle Ages.
The Walls of Constantinople
Sometimes known as "The Great Wall of Europe", the walls of Constantinople stood strong for centuries. Yet in 1453 they fell to the Ottoman Turks.