Battles & Wars › Gunpowder empires
Fall of Constantinople
April 6 – May 29, 1453· Battle· Europe
Well documentedSolid records, physical evidence or scientific consensus.
Mehmed II's Ottoman army captured Constantinople, capital of the Byzantine Empire, after a siege of nearly eight weeks.
See it on the Battles & Wars map →What happened
By 1453 the Byzantine Empire was little more than its capital, defended by perhaps 7,000–8,000 men, including Genoese and Venetian volunteers, against an Ottoman army estimated at 50,000–80,000. Huge Ottoman cannon battered the city's ancient land walls, and ships were hauled overland into the Golden Horn harbor. On May 29 a dawn assault broke through. Emperor Constantine XI died in the fighting, the city was sacked, and Hagia Sophia became a mosque.
Why it matters
It ended the Roman Empire's last remnant, made the Ottomans a European great power, and showed that cannon had made medieval walls obsolete.
How we know
Eyewitness accounts by the Venetian Nicolò Barbaro, the Byzantine official George Sphrantzes and others, Ottoman chronicles, and the surviving Theodosian Walls themselves.
Still debated
Constantine XI's body was never certainly identified, and the story that a small gate, the Kerkoporta, was left open, told by the chronicler Doukas, is doubted by many historians.
Inside this (5)
Connections (10)
▸Fall of Constantinople ended the last remnant of Roman EmpireWell documented
The connection
'Byzantine' is a modern label. The empire ruled from Constantinople was the eastern Roman Empire, which outlived the West by nearly 1,000 years and whose people called themselves Romans. When Constantine XI died on the walls in 1453, a line of Roman emperors reaching back to Augustus ended. Mehmed II then claimed the title 'Caesar of Rome'.
When and how
Constantinople (Istanbul), May 29, 1453; the last emperor, Constantine XI Palaiologos, and Sultan Mehmed II. The last Byzantine fragments, the Morea and Trebizond, fell in 1460–61.
How we know
Byzantine coins, laws and documents call the state and its people Roman (Rhomaioi) until 1453, and Ottoman and Western sources recognized that claim.
Debates and open questions
Whether medieval Byzantium 'counts' as Roman is partly definition; the Holy Roman Empire and Russia, as the 'Third Rome', also claimed Rome's inheritance.
▸Gunpowder and cannon breached the walls at Fall of ConstantinopleWell documented
The connection
Mehmed II hired Orban, a Hungarian cannon founder the Byzantines could not afford, to cast giant bombards. The largest, about 8 meters long, fired stone balls of roughly 500 kg a few times a day. For seven weeks dozens of guns pounded the thousand-year-old Theodosian Walls. Defenders patched breaches nightly, but the final assault came through the battered central section.
When and how
The land walls of Constantinople, April 6 – May 29, 1453; guns cast by Orban at Edirne and fired by Ottoman gunners.
How we know
The Venetian eyewitness Nicolò Barbaro and the Greek historian Kritoboulos describe the guns; the similar 1464 Dardanelles Gun survives in Britain's Royal Armouries.
Debates and open questions
Sources differ on the great gun's size and whether it cracked early; some historians argue numbers and the final assault mattered as much as cannon.
▸The Crusades weakened Byzantium long before Fall of ConstantinopleMostly agreed
The connection
The Fourth Crusade, diverted by debts to Venice and a Byzantine succession quarrel, captured and sacked Constantinople in 1204 and set up a Latin empire there. The Byzantines retook the city in 1261, but the empire never recovered its wealth, territory or navy. Shrunken and poor, it could not stop the rising Ottomans, who took it in 1453.
When and how
Constantinople, April 1204; crusaders and Venetians under Doge Enrico Dandolo and Boniface of Montferrat; Latin rule lasted until 1261.
How sure are we?
Eyewitnesses Geoffrey of Villehardouin, Robert de Clari and the Byzantine Niketas Choniates describe the sack; the bronze horses of St Mark's in Venice were part of the loot.
Debates and open questions
Historians debate how much 1204, rather than later civil wars, plague and Ottoman strength, explains the fall of 1453.
▸Mehmed II the Conqueror commanded the Ottomans at Fall of ConstantinopleWell documented
The connection
Mehmed II prepared for over a year. He built the Rumeli Hisarı fortress in 1452 to close the Bosporus, hired Orban to cast giant guns, and gathered a large army and fleet. When a chain blocked the Golden Horn harbor, he had about 70 ships dragged overland on greased rollers into it. On May 29 he ordered the final assault.
When and how
Constantinople, spring 1453; Mehmed, aged 21, and commanders such as Zaganos Pasha, against Constantine XI and the Genoese captain Giovanni Giustiniani.
How we know
Kritoboulos, a Greek who served Mehmed, wrote his biography, and Byzantine and Venetian eyewitnesses describe his orders, including the overland move of ships.
Debates and open questions
The route and number of ships moved overland differ between sources, as does how close Mehmed came to calling off the siege.
▸Fall of Constantinople anchored the Ottoman push into Europe halted at Siege and Battle of Vienna (1683)Mostly agreed
The connection
Taking Constantinople in 1453 gave the Ottomans a capital bridging Europe and Asia and a base for pushing into the Balkans. Over two centuries they took Serbia and most of Hungary, and first besieged Vienna in 1529. The 1683 siege was the last great advance of that push; its failure began a long Ottoman retreat.
When and how
From Constantinople, taken by Mehmed II in 1453, through the victory at Mohács in 1526 and the first Vienna siege in 1529, to Vienna in 1683.
How sure are we?
Each step of Ottoman expansion is well documented; the link itself is a broad historical arc rather than a single cause, which is why it is rated mostly agreed.
Debates and open questions
Whether the Ottoman Empire was already declining before 1683 or was still strong is a lively debate among historians.
▸Battle of Manzikert began the Byzantine decline that ended in Fall of ConstantinopleMostly agreed
The connection
Losing central Anatolia stripped Byzantium of its main recruiting ground and tax base. The empire partly recovered under the Komnenos emperors, but was weakened further by the Fourth Crusade's sack of Constantinople in 1204 and by Ottoman expansion. When the Ottomans took the city in 1453, the empire was little more than its capital.
When and how
From Manzikert in eastern Anatolia, 1071, to Constantinople (now Istanbul), May 29, 1453.
How sure are we?
The territorial losses are well documented; treating 1071 as the start of a single decline is an interpretation that many historians now challenge.
Debates and open questions
Many historians argue the 1100s revival shows 1071 was not fatal, and that the 1204 sack did more lasting damage than Manzikert.
▸Battle of Kosovo (1389) opened the Balkans to the Ottomans before Fall of ConstantinopleWell documented
The connection
Kosovo left Serbia too weak to resist. Lazar's son Stefan Lazarević became an Ottoman vassal, sending troops on Ottoman campaigns. With most of the Balkans under their control, the Ottomans could surround Constantinople by land. They took it in 1453, 64 years after Kosovo.
When and how
Kosovo Polje, June 15, 1389; Constantinople, April–May 1453. Sultans Murad I, Bayezid I and later Mehmed II.
How we know
Ottoman and Serbian records show Serbian vassal troops fighting for the sultans, as at Ankara in 1402, and the steady Ottoman advance through the Balkans.
Debates and open questions
Some historians see the Ottoman victory at the Maritsa River in 1371 as more decisive, since it had already broken Serbian power.
▸Battle of Ankara delayed by half a century Fall of ConstantinopleMostly agreed
The connection
Bayezid I had been blockading Constantinople since 1394. Defeat at Ankara forced him to lift it and plunged the Ottomans into an 11-year civil war among his sons. Byzantium even regained some territory. Only under Mehmed II, 51 years later, did the Ottomans finally take the city.
When and how
Ankara, July 1402; Constantinople, blockaded 1394–1402 and taken May 29, 1453.
How sure are we?
Byzantine sources describe the lifted blockade and the reprieve; Ottoman sources record the civil war, known as the Interregnum (1402–1413).
Debates and open questions
Whether Constantinople would have fallen without Timur is debated: its walls had withstood eight years of blockade, and Ottoman siege guns were still weak.
▸Bombards: giant siege guns battered the walls at the Fall of ConstantinopleWell documented
The connection
From April 6, 1453, Ottoman bombards fired stone balls at Constantinople's thousand-year-old Theodosian land walls. Walls built tall and thin for older siege methods cracked, and defenders patched them nightly with timber and earth. After seven weeks of bombardment, Ottoman troops broke in on May 29.
When and how
Land walls of Constantinople, April 6 – May 29, 1453; perhaps about 70 Ottoman guns in batteries.
How we know
Eyewitness accounts by Nicolò Barbaro and Leonard of Chios, and Byzantine historians, describe the gunfire and the damage.
Debates and open questions
How much the guns decided the outcome, versus Ottoman numbers and the defenders' exhaustion, is debated; one account says the break-in came through a small gate left open.
▸Orban and the Ottoman cannon foundries cast the guns that breached walls at the Fall of ConstantinopleWell documented
The connection
Orban's foundry produced the great bombard and other large guns, some cast near the siege lines. Grouped in batteries along the land walls, they fired for seven weeks, opening breaches that defenders could only patch. The final assault came through the battered walls on May 29.
When and how
Edirne and the siege lines outside Constantinople, 1452–1453.
How we know
Eyewitnesses describe the batteries and the damage, and several accounts name Orban as founder of the largest gun.
Debates and open questions
How many of the siege guns Orban cast himself, rather than other Ottoman founders, is unknown.