Ottoman Capture of Belgrade (1521): Suleiman's First Conquest

The Ottoman capture of Belgrade in 1521 was the first great victory of Sultan Suleiman the Magnificent. After a siege of about two months, the Hungarian fortress at the meeting of the Sava and Danube rivers surrendered on 29 August 1521. Belgrade had defied the Ottomans for decades, and its fall opened the way for the Ottoman conquest of Hungary.

Background

Belgrade, called Nándorfehérvár in Hungarian, had been the key fortress on Hungary’s southern frontier since 1427. It had already resisted two Ottoman sieges. Sultan Murad II failed to take it in 1440, and Mehmed II, conqueror of Constantinople, was driven off by John Hunyadi in the siege of Belgrade of 1456.

By 1521 the balance had shifted. Hungary, ruled by the 15-year-old King Louis II, was weakened by quarrels among the great nobles, a heavy debt burden and the aftermath of a major peasant revolt in 1514. Its southern fortresses were poorly paid and supplied.

The new sultan, Suleiman the Magnificent, came to the throne in September 1520 and wanted an early victory to establish his authority. Hungary had refused an Ottoman demand for tribute and had detained the envoy who delivered it; later accounts say the envoy was killed. This gave Suleiman a reason for war.

The campaign

Suleiman left Istanbul in May 1521 with a large army, often estimated at about 100,000 men, though exact numbers are unknown. He divided his forces. The grand vizier Piri Mehmed Pasha was sent ahead to besiege Belgrade, while the sultan himself attacked the fortress of Šabac (Szabács) on the Sava, which fell on 7 July 1521. Ottoman troops also took Zemun (Zimony) and other strongholds nearby, cutting Belgrade off from the north.

Ottoman engineers built a bridge across the Sava so that the army could cross. Suleiman then joined the siege of Belgrade in person.

The siege and surrender

The defenders were few. The garrison is often said to have numbered only around 700 soldiers, many of them Serbian, and its senior commanders were absent, leaving deputies in charge. The Hungarian court called for a relief army, but it gathered too slowly, and requests to Charles V, the pope and other rulers brought no effective help.

Ottoman artillery bombarded the walls, including from positions on an island in the river, and the attackers launched repeated assaults. Mines were exploded beneath the walls, and the outer town fell. The defenders retreated into the citadel, where supplies and morale ran out.

On 29 August 1521 the garrison surrendered. The defenders were promised safe conduct, but according to several accounts many of the Hungarian soldiers were killed afterwards. The main church in the citadel was converted into a mosque, where Friday prayers were held in the sultan’s presence.

Part of the Serbian population of Belgrade was deported to Istanbul. They were settled in a village in the forests north of the city that became known as Belgrade, and the area is still called the Belgrade Forest.

Key people

• Suleiman I (1494–1566), Ottoman sultan from 1520, later called the Magnificent in Europe and the Lawgiver in Turkey. Belgrade was the first campaign he led as sultan.
• Piri Mehmed Pasha (died c. 1532), grand vizier inherited from Selim I, who opened the siege of Belgrade. He was replaced as grand vizier by Ibrahim Pasha in 1523.
• Louis II (1506–1526), king of Hungary and Bohemia, whose government failed to relieve the fortress. He died fleeing the battlefield at Mohács five years later.

Timeline

• 1440: Murad II fails to take Belgrade.
• 1456, July: John Hunyadi defeats Mehmed II at Belgrade.
• 1520, 30 September: Suleiman becomes Ottoman sultan.
• 1521, May: Suleiman leaves Istanbul on campaign.
• 1521, 7 July: Ottoman forces take Šabac on the Sava.
• 1521, 29 August: Belgrade surrenders to Suleiman.
• 1526, 29 August: Ottoman victory over Hungary at Mohács.

Consequences

With Belgrade in Ottoman hands, Hungary’s southern defences collapsed. The fortress became the main Ottoman base for campaigns north along the Danube. Five years later, on 29 August 1526, Suleiman’s army destroyed the Hungarian royal army at the Battle of Mohács, where King Louis II was killed. Much of Hungary was soon divided between the Ottomans and the Habsburgs.

Belgrade developed into an important Ottoman city of mosques, markets and caravanserais, a trading centre linking the Balkans and Central Europe. It changed hands several times in later wars: the Habsburgs captured it in 1688, 1717 and 1789, but the Ottomans each time recovered it. The last Ottoman troops left the fortress in 1867, when it was handed over to the Principality of Serbia.

Why it matters

The capture of Belgrade was Suleiman’s first major success and the turning point in the Ottoman-Hungarian wars. It removed the barrier that had held back the Ottomans for almost a century and led directly to Mohács and the partition of Hungary.