Siege of Belgrade (1456): John Hunyadi Halts Mehmed II

The siege of Belgrade took place in July 1456, when Ottoman Sultan Mehmed II, three years after conquering Constantinople, attacked the Hungarian fortress of Belgrade at the meeting of the Danube and Sava rivers. A relief force led by the Hungarian general John Hunyadi and an army of volunteer crusaders gathered by the Franciscan friar John of Capistrano broke the siege on 22 July. The victory stopped the Ottoman advance into Central Europe for some 70 years and is still remembered in the tradition of the noon bell.

Background

Belgrade, called Nándorfehérvár in Hungarian, guarded the main route from the Balkans into the Hungarian plain. Serbian rulers had handed it to Hungary in 1427, and it became the kingdom’s key southern fortress. Sultan Murad II had already besieged it unsuccessfully in 1440.

After the fall of Constantinople in 1453, the young and ambitious Mehmed II prepared to strike north. He had conquered much of Serbia in 1454 and 1455, and Belgrade was the natural next step towards Hungary.

Hungary was poorly prepared. The young King Ladislaus V and the great nobles distrusted John Hunyadi, the former regent and the kingdom’s most experienced commander, whose earlier campaigns had ended in defeat at the Battle of Varna in 1444 and at Kosovo in 1448. When the danger became clear, the king left for Vienna, and much of the burden fell on Hunyadi himself.

Pope Callixtus III, elected in 1455, was eager for a crusade. He sent preachers across Central Europe, the most famous being John of Capistrano, a 70-year-old Italian Franciscan whose sermons drew large crowds of peasants, townsmen, students and minor nobles.

The siege

Mehmed II arrived before Belgrade in early July 1456 and began the siege on 4 July. His army is variously estimated at between about 60,000 and 100,000 men, supported by a substantial artillery train and a river fleet that blocked the Danube. The garrison, commanded by Hunyadi’s brother-in-law Mihály Szilágyi, numbered perhaps 5,000 to 7,000 men.

Ottoman guns battered the walls for days. Meanwhile Hunyadi assembled a relief force of his own troops and a river flotilla, while Capistrano’s crusaders, poorly armed but numerous, gathered nearby. Contemporary figures for the crusaders vary greatly, and modern estimates suggest several tens of thousands at most.

On 14 July Hunyadi’s flotilla attacked the Ottoman ships blockading the Danube. After hours of fighting, the blockade was broken and the relievers were able to bring men and supplies into the fortress.

On 21 July Mehmed ordered a general assault. Ottoman troops broke into the town and fought through the night, but the defenders threw burning materials into the moat and drove them back. The Hungarian tradition of Titusz Dugovics, who is said to have pulled an Ottoman flag-bearer from the walls and fallen with him, belongs to this episode, though it is not confirmed by contemporary sources.

The battle of 22 July

On 22 July some of the crusaders, without orders, crossed out of the fortress and began skirmishing with Ottoman troops. More joined them, and Capistrano, at first trying to restrain them, went out to lead them. The fighting spread into a general battle. Hunyadi seized the moment and launched an attack from the fortress, capturing Ottoman artillery positions and turning the guns on the besiegers.

Mehmed II was wounded during the fighting, reportedly by an arrow in the thigh. That night the Ottoman army lifted the siege and withdrew towards Constantinople, leaving behind guns and supplies. Ottoman losses were heavy, though figures in the sources are unreliable.

Why the defence succeeded

Several factors explain the outcome. Belgrade was a strong position, protected on two sides by wide rivers and on land by walls and an inner citadel, so the besiegers could not easily surround it completely. Once the Ottoman blockade on the Danube was broken on 14 July, the defenders could be reinforced and resupplied by water, which undermined the logic of the whole siege.

Hunyadi also had long experience of fighting Ottoman armies and understood their methods. He made good use of river boats, which the Ottomans had difficulty countering, and he was able to exploit the confusion created when the crusaders attacked on their own initiative on 22 July. Capturing the Ottoman guns and turning them on their owners was decisive in breaking the besiegers’ morale.

Finally, religious enthusiasm played a real part. Contemporary accounts, many of them written by Franciscans close to Capistrano, stress the zeal of the crusaders, who were willing to attack trained soldiers despite their poor equipment. These accounts glorify the friar’s role and sometimes minimise Hunyadi’s, and historians have long debated how to divide the credit between the two men. Most now agree that the victory needed both: Hunyadi’s professional troops and fleet, and the large numbers and determination of Capistrano’s volunteers.

The Ottomans, for their part, had suffered heavy losses in the failed assault of 21 July, and the sultan’s wound removed his personal leadership at the critical moment. Some Ottoman sources play down the defeat, presenting the withdrawal as an orderly decision, but it is clear that Mehmed’s army abandoned much of its equipment.

Key people

• John Hunyadi (c. 1407–1456): Hungarian general and former regent, commander of the relief.
• John of Capistrano (1386–1456): Franciscan preacher who raised and led the crusader volunteers; later canonised.
• Mehmed II (1432–1481): Ottoman sultan and conqueror of Constantinople.
• Mihály Szilágyi: Commander of the Belgrade garrison and Hunyadi’s brother-in-law.
• Pope Callixtus III: Pope who promoted the crusade and ordered the noon prayer bell.

Consequences

The victory had a high cost. Plague broke out in the Christian camp, and John Hunyadi died of it on 11 August 1456 at Zimony (Zemun), across the river from Belgrade. Capistrano died on 23 October. Hunyadi’s death led to a bitter power struggle in Hungary, in which his elder son László was executed in 1457. In 1458 his younger son was elected king as Matthias Corvinus.

Mehmed II never again led a major campaign into the Hungarian kingdom itself. He turned to finishing the conquest of Serbia, Greece and Bosnia, and much of the Balkans was incorporated into the Ottoman Empire over the next decade. Belgrade stayed in Hungarian hands until 1521, when Suleiman the Magnificent took it in the Ottoman capture of Belgrade.

The noon bell

On 29 June 1456, before the siege began, Pope Callixtus III issued a bull ordering church bells to be rung each day around midday, calling believers to pray for those fighting the Ottomans. In several places the news of the victory arrived soon after the order, so the bell came to be seen as a celebration of the triumph at Belgrade.

News of the victory reached Rome on 6 August 1456. In 1457 Callixtus extended the Feast of the Transfiguration, held on 6 August, to the whole Western Church in thanksgiving. In Hungary and among Catholics in Central Europe the noon bell is still widely associated with Hunyadi’s victory.

Timeline

• 1427: Belgrade passes from Serbian to Hungarian control.
• 1440: Murad II besieges Belgrade without success.
• 1456, 29 June: Callixtus III orders the noon prayer bell.
• 1456, 4 July: Mehmed II begins the siege.
• 1456, 14 July: Hunyadi’s flotilla breaks the Ottoman blockade on the Danube.
• 1456, 21 July: The general Ottoman assault is repulsed.
• 1456, 22 July: Crusaders and Hunyadi rout the besiegers; Mehmed II withdraws that night.
• 1456, 11 August: Hunyadi dies of plague.
• 1456, 23 October: John of Capistrano dies.

Why it matters

The siege of Belgrade was the greatest Christian victory over the Ottomans in the fifteenth century. It halted Mehmed II’s advance towards Central Europe for a generation, kept Hungary as a barrier state until the sixteenth century and gave Europe an enduring daily reminder of the battle in the ringing of the noon bell.