The Fall of Constantinople

The Fall of Constantinople
April 6, 1453 – May 29, 1453

The fall of Constantinople in 1453 shook Europe to its core. However, its causes can be traced back centuries prior. During the 12th century, the Byzantine Empire began to decline. For over 300 years, its capital’s population decreased from 400,000 to 40-50,000. As a result of multiple sieges, Constantinople’s citizens either died or had to migrate.

As Constantinople’s population dropped, its relationship with Europe worsen. Events within the Catholic church created a divide between Orthodox Byzantines and Catholic Europeans. Because of this, mutual distrust and hatred existed between both groups. Despite the animosity, Europeans still viewed the Byzantine Empire as its last line of defense against the Ottomans.

Ottoman Empire

As the Byzantine Empire declined, the Muslim Ottoman Empire flourished. By the 1300s, the Ottomans began encroaching on Byzantine territory. As a consequence, the invaders started seizing cities along Constantinople. By 1400, the Ottomans desired to capture the Byzantine capital.

In 1422, the Ottoman leader, Sultan Murad II, began an assault on Constantinople. Murad prematurely ended his siege after a rebellion occurred in his empire. However, the sultan didn’t live to attempt another invasion. After his death, his son, Sultan Mehmed II, vowed to continue his father’s work.

Mehmed II

Mehmed II
Mehmed II

Initially, Europe and the Byzantine Empire didn’t view Mehmed II as a threat. Mehmed was only 18-years-old when he became sultan. He had yet to consolidate control over the Ottomans. Regardless, the young ruler possessed a sharp mind and quickly proved to be an adept leader. After establishing his authority, Mehmed started preparing for an invasion of Constantinople.


Mehmed II understood that if his invasion were to succeed, he needed to make diplomatic efforts in Europe. To this end, the sultan made peace treaties with Hungary and Venice. As two of the Ottoman’s biggest threats, the agreements effectively neutralized them. Mehmed next focused on military equipment.

Mehmed II recognized that Constantinople’s greatest defense was its walls. In response, the sultan commissioned Urban, a Hungarian blacksmith, to build cannons. The cannons themselves were huge and of a large caliber. The sultan believed that these prototypes would prove crucial in his invasion.

In March 1453, the newly constructed cannons were positioned on Constantinople’s outskirts. In April, Ottoman forces captured settlements along the Byzantine coast. By May, Mehmed II departed to join his army. During this time, the Byzantine Emperor, Constantine XI, became aware of the upcoming invasion. Alarmed, the emperor reached out to Europe for help.

The Emperor’s Plea

Constantine XI
Constantine XI

Despite the importance of Constantinople, Europe’s response proved to be lackluster. Some rulers, such as Henry VI of England, were dealing with their own domestic issues and couldn’t provide aid. Other rulers were at war with each other. Since Europe’s political climate was in disarray, Constantine’s plea fell on deaf ears.

Instead of providing aid, Pope Nicholas V took advantage of Constantinople’s situation. He called for the reunification of the Orthodox and Catholic churches. Because of its treaty, Hungary ignored Constantine’s plea. However, Venice responded favorably. Despite their treaty with the Ottomans, the Italian city-state sent troops and ships to Constantinople. Unfortunately, only a small amount of aid made it in time.


On April 6, 1453, Mehmed II and his forces launched an assault on Constantinople. Constantine XI felt confident in his capital’s defenses. The city’s walls had never been breached, and it was believed that they could repel a naval attack. Despite his optimism, Constantine’s forces were significantly smaller than Mehmed’s. While Constantine had between 6,000-7,000 troops, Mehmed had 60,000-80,000.

As Constantine XI desperately waited for reinforcements, Mehmed II’s army enacted his plan. The sultan began by using his many warships to blockade Constantinople. Next, his forces started firing their cannons at the city’s walls. The cannons leveled a section of the wall, and Ottoman soldiers invaded. On April 7, the Byzantine soldiers repelled the attack and began making repairs.

One of the most significant deterrents during the siege was the golden chain. The Byzantines laid this massive, metal chain across a crucial waterway called the Golden Horn. After his navy couldn’t overcome the chain, Mehmed II fixated on capturing the Golden Horn. The sultan created a cunning plan to overcome the chain by transferring his smaller ships above ground. The plan’s success allowed the Ottomans to bypass one of Constantinople’s primary defenses.

The Ottoman’s Advantage

After overcoming the golden chain, Mehmed II’s forces surrounded Constantinople. Despite small sections of the walls crumbling, Byzantine troops continued to fight off Ottoman attacks. Repairs were continually made. However, with the cannons in place, the walls suffered repeated barrages. After three unsuccessful attacks, the fourth Ottoman assault captured an inner wall. This capture proved to be a significant turning point during the siege.

Constantinople Falls

Mehmed II’s forces capitalized on their new foothold. Ottoman soldiers rushed into the city and overwhelmed the Byzantines. The Byzantine defenders were routed, and many foreign troops fled. As the city fell, so too did Constantine XI. In the end, the emperor died fighting in the streets. Wishing to avoid a complete sacking of the capital, Mehmed rewarded his troops with a short period to loot.

With the emperor dead and the empire subjugated, the Ottomans had secured Constantinople. Shortly after, the looting stopped. To symbolize Muslim control, the Christian cathedral of Hagia Sophia converted into a mosque. Subsequently, Constantinople became Istanbul, which established it as the Ottoman Empire’s new capital. Through these actions, the sultan made it clear to Europe that the Byzantine Empire had ceased to exist.


The fall of Constantinople sent shock waves throughout Europe. After May 29, 1453, Europeans no longer had a defensive barrier against the Ottoman Empire. Now, the Ottomans were on Europe’s border and controlled the important Black Sea. Consequently, Europe had to rely on the weaker Hungary as their last line of defense. As a result, the Ottomans would use this to their advantage during the following century.


Hudson, M. (2019, August 29). Fall of Constantinople. Retrieved January 10, 2020, from

Miller, M. (2019, July 20). The Fall of Constantinople: Relentless Ottoman Fire Power Finally Pulverizes the Last Vestiges of the Roman Empire. Retrieved January 10, 2020, from

May 29, 1453, The Fall of Constantinople. (2019, May 29). Retrieved January 10, 2020, from


Andy Tree

I'm a European history enthusiast who seeks to share his passion with others. I hope to inform and inspire readers with my posts!

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