The Fall of Constantinople (29 May 1453)

The fall of Constantinople is one of the medieval events best documented by its contemporaries. Four narrative traditions coexist: Greek, Western Latin, Ottoman and Russo-Slavic. None is neutral; all are indispensable.

The Greek witnesses

Four Greek authors recount the fall. Three are contemporaries; the fourth is a famous but valuable forger.

Doukas, of whom we know only the family name, is a Catholic Greek of Lesbos, secretary to the Genoese lord of the island. His Historia Turco-Byzantina covers the years 1341–1462. He was not in Constantinople in May 1453, but he questioned survivors shortly afterwards and he knows the Ottoman world well. The Romanian medievalist Vasile Grecu established the reference critical edition in 1958^[10].

George Sphrantzes, chamberlain and personal confidant of Constantine XI, is probably the only member of the imperial government whose testimony has come down to us directly. His Chronicon Minus, short and factual, is unanimously recognised as authentic. The Chronicon Maius attributed to him in the tradition is in reality a sixteenth-century rewriting by Macarios Melissenos, an exiled Greek metropolitan: Melissenos embroidered, added speeches, but did not wholly invent the facts. The critical edition of the Maius by Vasile Grecu (Bucharest, 1966, introduction pp. 5–39) sets out this attribution to Macarios Melissenos and confirms the authenticity of the Minus — a distinction established by scholarship since 1934^[11].

Laonikos Chalkokondyles, a pupil of Georgios Gemistos Plethon at Mistra, wrote c. 1480 his Apodeixeis Historion, in Atticising Greek in the manner of Thucydides. He is less reliable on detail but valuable for understanding the Hellenising and already nostalgic gaze of a Byzantine of the last generation^[12].

Critobulus of Imbros, also a contemporary, is unique: he writes in Greek for Mehmed II, to whom he dedicates his work. His version is apologetic towards the Sultan, but it preserves a mass of irreplaceable military and administrative detail. His critical edition by Diether Reinsch (1983) has made it a major source^[13].

The Western Latin witnesses

Three Italians present during the siege left remarkable accounts.

Nicolo Barbaro, ship's surgeon of the Venetian fleet, kept throughout the siege a day-by-day log in Italian (Venetian). This Giornale dell'assedio di Costantinopoli is the most precise narrative source on the chronology of the siege: Barbaro notes the phases of the moon, the winds, the Venetian dead by name, the rumours of the day. First edited by Enrico Cornet in Vienna in 1856, translated into English by J. R. Jones in 1969, it has become the basis of all modern reconstructions of the calendar of operations^[14].

Leonard of Chios (Leonardo Giustiniani), Latin archbishop of Mytilene, present in the city throughout the siege, wrote on 16 August 1453, barely two and a half months after the fall, a letter to Pope Nicholas V of some twenty pages: it is the first detailed report received in Rome. A Greek Catholic by origin, he knew the Byzantine liturgy and spoke Greek and Latin. His text is extremely hostile to the Orthodox "schismatics", whom he holds responsible for the disaster because of their refusal of union with Rome — the grievance crystallised by the famous formula attributed by Doukas to the Grand Duke Loukas Notaras (see below)^[15].

Isidore of Kiev, former Metropolitan of Kiev turned Roman cardinal after the Council of Florence, was sent to Constantinople by Nicholas V in 1452 as papal legate. Wounded during the assault, captured then freed for ransom, he too wrote to the Pope and to Cardinal Bessarion in July 1453. His letter, preserved in the Patrologia Graeca, is the most moving document sent by a direct Catholic witness^[16].

Other, briefer Western Latin accounts complete the picture: the letter of Angelo Giovanni Lomellino (Genoese podesta of Pera) to the Council of Genoa of 23 June 1453, written three weeks after the fall, is one of the first official documents received in the West^[17]. The testimony of Jacopo Tedaldi, a Florentine merchant present at Constantinople, supplies valuable figures on the losses^[18].

The Ottoman and Persian sources

On the Ottoman side, the official historian Tursun Beg, imperial secretary under Mehmed II and his successors, wrote c. 1488 his Tarih-i Ebül-Feth ("History of the Father of the Conquest"). It is the Ottoman palace version: Mehmed appears in it as the ideal Muslim sovereign, soldier-scholar, conscious heir of the imperial destiny^[19]. Alongside him, several fifteenth-century Persian and Arab chroniclers relay the event as a major Islamic triumph, in fulfilment of a prophetic hadith attributed to Muhammad announcing the capture of Constantinople — a hadith very often quoted in Ottoman propaganda^[20].

Modern historiography

The history of the fall was refounded in the twentieth century. Steven Runciman published in 1965 The Fall of Constantinople 1453, which became an English-language classic through its clear prose and its knowledge of the late Byzantine world; its pro-Orthodox and anti-Latin biases are criticised today, but the factual narrative remains solid^[21]. Donald M. Nicol, professor at King's College London, supplies with The Last Centuries of Byzantium (1972; 2nd ed. 1993) the broad political framework, and with The Immortal Emperor (1992) the scholarly biography of Constantine XI^[22].

Scholarly Ottoman historiography was refounded by Franz Babinger (Munich) with his monumental Mehmed der Eroberer und seine Zeit (1953), a classic still unreplaced^[23]. More recently, the English historian Roger Crowley popularised the event for the general public with 1453 (2005): a work of high-level popularisation, reliable on the military course of events^[24]. The reference academic synthesis on the technical aspects of the siege is today The Siege and the Fall of Constantinople in 1453 by Marios Philippides and Walter K. Hanak (Ashgate, 2011), 760 pages of source criticism, topography of the walls, and study of the artillery and the fleet^[25].

An empire reduced to its capital

At the beginning of the fifteenth century, the Byzantine Empire is no more than a shadow. It has lost, in two centuries, almost all its provinces. The sack of Constantinople by the Fourth Crusade in 1204, which installed a Latin Empire on the Bosphorus for fifty-seven years, broke the economic and demographic base of the state. When the Palaiologoi retake the city in 1261, they inherit a dilapidated capital and ruined finances^[26].

Over the fourteenth century, the Ottomans, a Turkish dynasty from north-western Anatolia, conquer Bursa (1326), then Adrianople (1369), which becomes their Balkan capital, and crush Serbia at Kosovo (1389). In 1396, at Nicopolis, the European crusade led by King Sigismund of Hungary and the future Duke of Burgundy John the Fearless is swept away. In 1444, it is the crusade of Varna, led by the young King of Poland and Hungary Wladyslaw III Jagiellon, that breaks in its turn; Wladyslaw dies on the battlefield^[27]. In 1448, the defender of the Balkans, John Hunyadi, loses in his turn the second battle of Kosovo.

On the eve of the siege, the territory of the Byzantine Empire is limited to: the city of Constantinople itself and its suburbs; a few enclaves in Thrace; the Despotate of the Morea (Peloponnese), governed by the brothers of the basileus; and the Empire of Trebizond on the Black Sea, a cognate but distinct dynasty. The population of the city, which numbered perhaps 400,000 to 500,000 inhabitants in the twelfth century, is estimated by modern scholars at between 40,000 and 50,000 souls in 1453^[28].

What keeps the city standing is a single thing: its walls. The Theodosian defensive system, begun in 413 under the reign of Theodosius II, runs for nearly six kilometres between the Golden Horn and the Sea of Marmara. Triple wall, moat, glacis: it is the most formidable urban defensive work of the entire Middle Ages^[29]. For a thousand years it held: against the Avars (626), the Arabs (674–678 and 717–718), the Bulgarians (813 and 913), the Rus (860, 907, 941), the Pechenegs, the Latin Crusaders (1203–1204, the single exception in history), the Ottomans themselves (the failed sieges of 1394–1402 and 1422). The inhabitants lived with the popular conviction that the city was impregnable by land.

The Council of union of Florence (1439)

To obtain military aid from the West, Emperor John VIII Palaiologos resolves, after years of hesitation, to conclude the union of the Churches. From 9 April 1438 to 6 July 1439, he takes part in person in the Council of Ferrara-Florence, accompanied by some 700 Greek clergy and laymen, including Patriarch Joseph II of Constantinople — who would die at Florence in June 1439^[30].

In his opening address of 9 April 1438, Bessarion proposes examining one by one, in the light of the Fathers, the four points dividing Latins and Greeks: the procession of the Holy Spirit, unleavened bread, purgatory and the primacy of the Pope^[31].

On 6 July 1439, in the cathedral of Santa Maria del Fiore, the decree of union Laetentur Coeli is solemnly promulgated: it defines the procession of the Holy Spirit from the Father and the Son (Filioque) as a dogma of faith, recognises the primacy of the Pope, and admits the Catholic doctrine of purgatory^[32]. The text is signed by all the Greek bishops present, with the exception of Mark of Ephesus, who refuses and would remain in the later Orthodox tradition the symbol of resistance.

At Constantinople, the reception is disastrous. Hostile theologians — foremost among them George Scholarios, the future first patriarch under Ottoman rule under the name Gennadios II — denounce the union as a betrayal of Orthodoxy. The population, workers, sailors, monks, perceive the decree as a capitulation. A formula attributed to the Grand Duke Loukas Notaras, the Emperor's first minister, circulates in the city:

"Rather see reigning in the midst of the city the Sultan's turban than the Latin mitre." — Loukas Notaras, as attributed by Doukas, Historia Turco-Byzantina, 37, 10^[33]

The formula, if authentic, is tragic: Notaras, his eldest son and his son-in-law would be beheaded by Mehmed II on personal order a few days after the fall^[34]. But it says something about the depth of the Orthodox refusal of the Florentine union — a refusal that would be paid for very dearly.

The arrival of Mehmed II (1451)

On 3 February 1451, at Adrianople, the Ottoman Sultan Murad II dies suddenly. His son Mehmed II, already Sultan once between 1444 and 1446, ascends the throne definitively. He is eighteen years old (he will celebrate his nineteenth birthday on 30 March). His mother is a slave probably Christian, perhaps Serbian or Greek; the sources diverge^[35]. He speaks Turkish, Persian, Arabic, Greek (which he learned very young), and reads the classics. He publicly identifies with Alexander the Great and Caesar^[36].

The Byzantine ambassadors sent to congratulate the new Sultan, in the summer of 1451, return reassured. Mehmed appears moderate, renews the treaties of peace concluded by his father, accepts to pay the annual pension agreed at Adrianople for the keeping, as a hostage at the Ottoman court, of Prince Orhan, a rival claimant to the Ottoman throne who had taken refuge at Constantinople. Doukas notes Byzantine satisfaction^[37].

But this moderation is a feint. From the autumn of 1451, Mehmed undertakes methodically to hunt down his Anatolian adversaries (the Karamanids), then turns towards Constantinople. The first alarming signal comes in March 1452: the Sultan orders the construction of a fortress on the Bosphorus, at the narrowest European point, 7 kilometres upstream of the city.

Rumeli Hisar, the prison-fortress

Construction begins on 15 April 1452 on the European shore of the Bosphorus, facing the Ottoman fortress of Anadolu Hisar (raised by Bayezid I in 1394). The worksite proceeds at an unheard-of pace: three thousand labourers work day and night. Mehmed personally supervises the works. On 31 August 1452, the fortress — called by the Turks Bogazkesen ("the throat-cutter" or "the strait-cutter") and later Rumeli Hisar — is completed. Three main towers, a hexagonal enclosure, cannon trained on the strait^[38].

The effect is immediate. On 26 November 1452, two Venetian galleys refuse to lower their sails and pay the toll: one, commanded by Antonio Rizzo, is sunk by cannon fire; the survivors are beheaded on the Sultan's order; the commander is impaled^[39]. The message is clear: all aid coming from the Black Sea through the Bosphorus — Pontic grain, Latin ships, troops — is henceforth impossible. Constantinople is cut off from one of its principal supply arteries.

The Ottoman arsenal and Orban's bombard

In the winter of 1452–1453, a founder of Hungarian origin, Orban (also transcribed Urban), first presents himself to the Byzantine emperor to sell his services. The basileus cannot afford them. Orban then passes over to Mehmed II, who grants him four times the salary asked of Constantine and all the materials he demands. At Adrianople, in the Sultan's courtyard, the master founder undertakes to cast the largest bronze cannon ever made^[40].

The figures reported by the chronicles are impressive. The great bombard is said to measure about 8.2 metres long, to fire stone balls of 540 to 680 kilograms, to require sixty oxen and four hundred men for its transport, and to need about three hours of cooling between two shots^[41]. Alongside this exceptional piece, Orban casts several dozen smaller cannon, which too would suffice to break sections of the Theodosian wall.

The Ottoman arsenal is not artillery alone. Mehmed mobilises some 120 to 160 ships at Gallipoli — an unprecedented fleet — elite janissaries (the ocak, infantry of Christian origin forcibly converted through the devshirme), Serbian miner-sappers specialising in underground warfare, and a corps of azabs (Muslim irregulars).

Forces present

The table below summarises the forces according to convergent modern estimates^[42].

The raw balance of forces is therefore about ten to one. But the Byzantines have on their side the walls, a massive bronze chain closing the entrance of the Golden Horn (at the Galata arsenal), and the military experience of a handful of seasoned Italian mercenaries.

Constantine XI Dragases Palaiologos (1405–1453)

Born on 8 February 1405 at Constantinople, Constantine Dragases Palaiologos is the fourth son of Emperor Manuel II and Helena Dragas, a Serbian princess. His surname Dragases comes from his mother. Despot of the Morea (Peloponnese) from 1428, he distinguishes himself there through a vigorous policy against the Latin principalities and by consolidating the northern frontier of the despotate. He ascends the imperial throne at Mistra, in the Morea, on 6 January 1449, after the death of his brother John VIII left no direct male heir, and enters Constantinople on 12 March 1449^[43].

Three traits dominate in him according to the sources. First, a deep personal piety but reticent towards the union of Florence, which he nevertheless ends up accepting for military reasons. Second, a courageous obstinacy: he repeatedly refuses to leave the city during the siege and, in the final negotiations, rejects Mehmed's offer to withdraw freely to the Peloponnese with his family if he surrendered Constantinople without a fight. Finally, a political solitude: throughout the siege, he is without real foreign aid beyond a few hundred Italians.

"What I can tell you is that, as for the city, neither I nor anyone living in it will surrender it to you. We are resolved to die all, and we shall not spare our lives." — Constantine XI to Mehmed II, final embassy, as reported by Sphrantzes, Chronicon Minus, 35^[44]

Mehmed II (1432–1481), called Fatih

Born on 30 March 1432 at Adrianople, Mehmed, third son of Murad II, ascends the throne a first time at the age of 12 (1444–1446), before returning definitively in 1451. His entourage trained him in war, diplomacy and letters. He knows the Greek classics, has Ptolemy and Plutarch translated for his use, reads Aristotle in Arabic^[45].

But Mehmed is above all a ruthless military strategist and a politician with a very long view. The capture of Constantinople is for him not only a stroke of prestige: it is the fulfilment of an Islamic spiritual mission, founded on Muhammad's hadith announcing to the believer the conquest of the Christian city. But it is also a project of imperial translation: Mehmed sees himself as the heir of the Caesars of the East. At the fall he would take the title of Kayser-i Rum, "Caesar of the Romans", a title the Ottoman sultans would formally bear until the end of the Empire^[46].

Giovanni Giustiniani Longo

The military soul of the defence is a Genoese: Giovanni Giustiniani Longo, a condottiere of about forty, of the merchant house of the Giustiniani of Chios. He arrives at Constantinople on 29 January 1453 with 700 men — 400 recruited at Genoa and 300 at Chios and Rhodes, his own armed retinue^[47]. Constantine XI immediately names him protostrator ("first of the strategoi") and entrusts him with command of the defence of the land walls, including the most exposed sector, that of the gate of Saint Romanus (Pege) and the valley of the Lycus where the terrain makes the defensive line most vulnerable.

Giustiniani is, in the Greek and Latin chronicles, the military hero of the whole campaign. He sleeps in arms, organises the rotations, has the sections of wall destroyed by Orban's cannon rebuilt every night, and calms the quarrels between Greek and Latin soldiers^[48]. His wounding and withdrawal, at dawn on 29 May, would be the direct cause of the collapse of the defence.

Cardinal Isidore of Kiev

The fourth actor, and the only one wearing the Roman purple: Isidore of Kiev (c. 1385–1463). Of Greek origin, former hegumen of the monastery of Saint Demetrios at Constantinople, he had been named in 1437 Metropolitan of Kiev and all Russia by Patriarch Joseph II — a see covering all the Ruthenian and Russian Christian lands. In 1439, at Florence, he signs the union of the Churches. In 1441, at Moscow, Grand Prince Vasily II has him arrested for treason, imprisons him, then lets him flee to Rome^[49].

At Rome, Pope Eugene IV creates him cardinal on 18 December 1439. In May 1452, Nicholas V sends him as legate to Constantinople to solemnly ratify the union, with 200 Neapolitan and Cretan archers engaged by Rome. On 12 December 1452, in the basilica of Hagia Sophia, Isidore sings the eucharistic liturgy according to the Byzantine rite in commemoration of the Pope (Nicholas V) and of the Greek Uniate Patriarch Gregory III, then a refugee in Rome. It is the last Uniate liturgy celebrated at Hagia Sophia^[50].

Wounded during the assault of 29 May, Isidore manages to disguise himself, to exchange his purple for the clothes of a corpse, to hide, then to be captured without being recognised. Sold as a slave in Asia Minor, he would be ransomed by the Genoese of Galata. He returns to Rome, where he dies on 27 April 1463, after actively pleading to the very end for a crusade^[51].

On 2 April 1453 (Byzantine Easter Monday), the first Ottoman units appear before the walls. The siege officially begins on 6 April 1453 with the full deployment of the army and the installation of the batteries. It would last fifty-three days^[52]. The chronological table below recapitulates the main phases^[53].

The first weeks: artillery and attrition

Orban's bombards pound the walls every day; the great bombard itself, which requires lengthy reloading and cooling of the bronze, can fire only a few shots a day, while the lighter pieces keep up a sustained fire^[54][55]. The Theodosian walls, designed to resist trebuchets, are not made to absorb projectiles of several hundred kilos striking at high speed. The section between the gate of Saint Romanus and the Pege gate, where the valley of the Lycus runs, becomes a field of rubble. But each night, Giustiniani and his men — soldiers, civilians, priests, monks, women — rebuild. Wood and packed earth serve as makeshift fortification. An infantry force attempting to cross this makeshift wall under Venetian crossbow fire would be bled white.

Carrying the galleys overland past Pera (21–22 April)

The most extraordinary episode of the siege is the overland crossing of the Ottoman fleet. The bronze chain closing the entrance of the Golden Horn from the tower of Eugenius, at the tip of the Constantinopolitan peninsula, to the Kastellion of Galata on the northern shore, prevents Turkish ships from entering the inner harbour. Mehmed then orders an unheard-of operation: to have built, in the night of 21–22 April, a road of planks greased with fat over the hill of Pera, about two kilometres long. On this track, more than seventy Ottoman galleys and transports are hauled on rollers by hundreds of oxen and thousands of men. By morning, the Ottoman fleet is in the Golden Horn, behind the chain, facing the weakest sea walls^[56].

The psychological shock is massive. Nicolo Barbaro writes in his journal:

"A thing appears, to whoever has seen it, more impossible than possible. And every sailor and man-at-arms who has sailed will say that it is a thing against nature." — Nicolo Barbaro, Giornale, 22 April 1453^[57]

The war of the mines (7–18 May)

For two weeks, the siege moves underground. The Ottoman Serbian sappers, specialists from the silver mines (they come from the silver mines of Novo Brdo), dig galleries under the walls. The tactic consists in bringing a chamber under a tower, shoring up the rock with timber, then setting fire: the collapse of the roof brings down the tower above^[58]. On the Byzantine side, the Saxon engineer Johannes Grant, in Giustiniani's pay, organises a systematic counter-mine: he has parallel galleries dug, sends in smoke, lights counter-fires, captures Serbian sappers who reveal the location of the other galleries. Fourteen mines are successively destroyed in eleven days.

The failure of Latin relief

On 3 May, a Venetian galley carrying twelve men disguised as Turks is sent through the naval blockade to locate the relief fleet promised by Venice. It returns on 23 May with terrible news: no fleet is coming. The Venetian Senate did vote to send fifteen galleys on 19 April, but administrative procedures, fitting out, loading of provisions took weeks. The ships are at Modon (Peloponnese) in May and will advance no further^[59]. Pope Nicholas V had five galleys armed at his own expense, laden with archers and arquebusiers, which leave Civitavecchia too late to reach Constantinople in time^[60]. As for Hungary and the fleet of Alfonso V of Aragon, their preparations remain purely declaratory.

The last common liturgy at Hagia Sophia

On the evening of Monday 28 May 1453, sensing that the decisive assault is imminent, Constantine XI gathers his Greek and Latin commanders. All know it will be the last night. A great solemn procession crosses the city, carrying the icon of the Hodegetria, the great Marian icon of the cathedral. Towards evening, the icon is laid in Hagia Sophia.

There, in the basilica with its golden mosaics, Greeks and Latins celebrate together the Divine Liturgy according to the Byzantine rite. The theological quarrels over the Filioque, papal primacy, purgatory and unleavened bread are, for a few hours, suspended. Cardinal Isidore of Kiev and the Greek Uniate metropolitan are at the altar; the Latin and Greek defenders receive communion together. Many weep. Constantine XI takes the floor: he forgives and asks forgiveness of each, embraces his officers, and addresses them in a speech that Sphrantzes reports in reconstituted form^[61].

"My brothers and fellow-combatants, be ready for the morning. I entrust to you, by the grace and mercy granted to me from above, your crown — not for yourselves, but for your descendants. And now, I render the city to you." — Speech of Constantine XI on the night of 28 May, in the version transmitted by Sphrantzes, Chronicon Minus, 35^[62]

Around midnight, he rides to the walls. The last earthly procession of the city's Christian relics dies out in the alleyways. The soldiers take their posts.

The general assault (29 May 1453, c. 1:30 a.m.)

Mehmed launches three successive waves. The first is made up of azab irregulars and bashi-bazouk Christians converted or enrolled by force: cannon fodder, meant to wear down the defenders. The second wave is made of Anatolian regulars. When waves 1 and 2 are exhausted and the defenders are themselves at the end of their strength, Mehmed launches the third wave: the janissaries, his elite infantry, along with his own guard troops^[63].

It is at this moment, around 5 a.m., that Giovanni Giustiniani Longo is wounded by a projectile (probably a crossbow bolt or a culverin fragment; the sources vary) striking him in the arm, chest or leg according to the versions. He signals that he is leaving the fight to be treated. Constantine XI begs him to stay: in vain. Giustiniani comes down from the walls, crosses the city, boards his galley and sails for Chios. He would die of his wounds at the beginning of June, on the way to Chios^[64].

Giustiniani's departure — interpreted by the Genoese as a forced medical retreat, by the Greeks as a betrayal — triggers panic among the Italian troops. At the same moment, a few hundred metres to the north, a small group of janissaries discovers that a postern, the Kerkoporta ("little gate"), has been poorly closed after a previous Christian sortie. Some fifty men rush through it^[65]. They immediately raise the Ottoman standard atop the neighbouring tower. The rumour that the city is taken spreads along the walls.

The death of Constantine XI

Seeing the Ottoman banners flying over the inner walls, Constantine XI tears off his imperial insignia and throws himself into the fray like a common soldier. All witnesses agree: he dies fighting, at the gate of Saint Romanus or very near. His body, after the capture, was never identified with certainty. Several accounts speak of a corpse found in imperial purple boots and cut up by Mehmed as proof, its head said to have been publicly exposed for some days^[66].

"Now the emperor, seeing that he could do nothing more, drew his sword and threw himself into the fray. Thus he died, and even his body was never found. Sultan Mehmed, alerted, ordered search to be made among the dead. A body in purple boots was found; the head was brought to the Sultan, who had it recognised by former captives of the court. And Mehmed had it sent, embalmed, to the principal capitals of the East." — Doukas, Historia Turco-Byzantina, 39, 26^[67]

By sunset that 29 May 1453, the Eastern Roman Empire no longer existed. Its imperial line, unbroken since 330, since Constantine I, had just been extinguished in an unidentified alleyway.

The three days of pillage

According to Ottoman custom, a city taken by assault after resistance could be delivered to the pillage of the victorious army. Mehmed granted this pillage, then quickly put an end to it to preserve his new capital: in practice, the massive sack was concentrated on the afternoon of 29 May and the hours that followed. The exact scale and duration of the pillage — one to three days according to the accounts — remain debated among historians^[68]. Ottoman soldiers pillage houses, churches, monasteries. Civilians remaining in the city take refuge en masse at Hagia Sophia, hoping the basilica will be respected. It is not: the door is smashed in, the faithful torn from the altar, killed on the spot or reduced to slavery^[69].

"On that Tuesday were seen things that cannot be told: women dragged by the hair, infants torn from the breast, blood flowing in the streets, and not a single house that was not ravaged." — Doukas, Historia Turco-Byzantina, 39, 18^[70]

The precise figures of the massacre of 29 May and the two following days remain debated. The commonly accepted estimates put forward about 4,000 persons killed and 30,000 reduced to slavery, out of a population of about 50,000 inhabitants^[71]. The rhetorical medieval figures of "40,000 dead" found in some chroniclers are today considered exaggerated.

The Grand Duke Loukas Notaras — the supposed author of the formula on the turban and the mitre — is captured alive, presented to Mehmed, then executed with his eldest son a few days later. Doukas reports the scene with an almost liturgical precision, suggesting the historian holds it from a witness present in the Sultan's court^[72].

Mehmed at Hagia Sophia

In the afternoon of 29 May, Mehmed II enters the city through the Adrianople gate (Edirnekapi). He rides to Hagia Sophia, dismounts, takes a handful of dust and pours it over his turban — a ritual gesture of submission to God after a victory. He enters the basilica. A soldier is in the process of prising loose a marble slab. Mehmed strikes him with the flat of his sword, reminding him that material booty belongs to the army, but that the buildings belong to the Sultan^[73].

Then he orders an imam to mount the ambo and proclaim the shahada there. Hagia Sophia, a Christian basilica since its consecration by Justinian on 27 December 537, becomes a mosque from that afternoon of 29 May 1453 — the first great Friday prayer being celebrated there on the following 1 June. It would remain so for 481 years, until its transformation into a museum by Ataturk in 1934; since 24 July 2020, it is once again a mosque^[74].

The fate of the inhabitants

The fate of the Greek Christian inhabitants is henceforth that of dhimmis under Muslim rule: tolerated subject to payment of the jizya (poll tax), forbidden to bear arms, to ride horses, to ride prestigious mounts, to testify in court against a Muslim, to repair or build churches without authorisation. A few months after the fall, Mehmed names George Scholarios — the leader of the anti-unionist party at Florence — Ecumenical Patriarch under the name of Gennadios II, and personally hands him the pastoral staff during a ceremony at the palace. Mehmed thus took up the ancient role of the Byzantine emperors as kataphylax ("protector") of the Church, but as Ottoman sultan.

The building of the new patriarchate, the system of the millet (autonomous religious communities under Ottoman authority), and the stabilisation of a Christian life under constraint would last five centuries at Constantinople become Istanbul.

The end of the Byzantine Empire

29 May 1453 marks the de facto end of the Eastern Roman Empire. But a few Greek enclaves survive some years: the Despotate of the Morea falls in May 1460; the Empire of Trebizond capitulates on 15 August 1461^[75]. The political fiction of a surviving imperial dynasty — around Thomas Palaiologos, brother of Constantine XI, a refugee in Italy with his daughter Zoe, the future Empress of Russia under the name Sophia Palaiologina — would long feed Latin hopes, but with no military sequel.

The scholarly diaspora and the Renaissance

Even before the fall, several Greek intellectuals had settled in Italy — Manuel Chrysoloras at Florence c. 1397, Georgios Gemistos Plethon at Florence in 1438–1439, Cardinal Bessarion at Rome after the Council. The fall accelerates the movement: dozens of Greek scholars, carrying manuscripts, philological methods and liturgical knowledge, head for Venice, Florence, Padua, Rome. Bessarion sends to the Serenissima, in 1468, 482 Greek manuscripts and 264 Latin books: with the complementary bequest received after his death, the collection reaches about a thousand items (1474 inventory) and founds the Biblioteca Marciana of Venice^[76].

The civilizational effect is considerable. The Greek scholars bring a direct knowledge of Plato, Aristotle, the Greek Fathers (Origen, Athanasius, Gregory of Nazianzus, John Chrysostom, Cyril of Alexandria) which the West had known only through medieval Arabo-Latin translations. It is one of the principal ferments of the Renaissance.

Moscow, "Third Rome"

At Moscow, the disappearance of Constantinople and the Latinising union of Florence — judged by the Russians as a betrayal — supply the young Muscovy with a new religious legitimacy. The marriage of Grand Prince Ivan III to Zoe/Sophia Palaiologina — marriage by proxy at Rome, wedding celebrated at Moscow on 12 November 1472 — symbolises the translatio imperii to Russia^[77]. Under Vasily III, the monk Philotheus of Pskov writes, c. 1510, to the Emperor:

"Two Romes have fallen; the third stands; and there shall be no fourth. For thy Christian kingdom, O most holy prince, shall pass to none other." — Philotheus of Pskov, letter to Vasily III, c. 1510^[78]

This doctrine of the Third Rome would durably mark the religious and political identity of Russia down to today^[79].

The failure of the crusade plans

In the months following the fall, Pope Nicholas V publishes on 30 September 1453 the bull Etsi Ecclesia Christi calling for crusade. His successor Callixtus III (1455–1458) devotes the bulk of his pontificate to it: he lives poorly, has the silver plate of the pontifical palace melted down to arm a fleet, and finances the victorious defence of Belgrade by Hunyadi on 22 July 1456 — the last true Christian military victory against the Ottomans before the sixteenth century^[80].

It is then Pius II (1458–1464), the former Aeneas Silvius Piccolomini, who devotes all his energy to mounting the great crusade. On 22 October 1463, he solemnly proclaims the crusade with the bull Ezechielis Prophetae. On 18 June 1464, ill, he has himself carried on a litter to Ancona to embark in person with the Venetian fleet. He dies at Ancona on 14 August 1464, two days before the arrival of the Venetian galleys; the crusade collapses with him^[81].

The failure of the post-1453 crusades — through European weariness, princely indifference, coming confessional divisions with Luther — is one of the great structuring facts of the century. The Ottoman threat would culminate at the siege of Vienna (1529) under Suleiman, be halted at Lepanto (7 October 1571) at sea, then broken at Vienna (12 September 1683) on land by John Sobieski. But Constantinople itself would remain Ottoman.

A "divine punishment"?

From the summer of 1453, several Latin authors read the fall as a divine chastisement for the Greek schism. Leonard of Chios is the most virulent: according to him, the Byzantines having refused in practice the union of Florence, God permitted the fall to show the falsity of the Orthodox refusal^[82]. Conversely, George Scholarios, the future Patriarch Gennadios II, sees in the fall the punishment of the Greeks for having signed the union at Florence, a union he judged simoniacal and heretical^[83]. The two camps, Latin Catholic and Orthodox, throw the providential responsibility back at each other.

The Catholic Church has never formally adopted this language of "divine punishment" to interpret the fall. The classical theology of divine providence distinguishes what God wills from what He permits. The Catechism of the Catholic Church, taken up in the Compendium presented and promulgated by Benedict XVI on 28 June 2005 — a text commissioned by Saint John Paul II — recalls:

"God is in no way, directly or indirectly, the cause of moral evil." — CCC, § 311^[84]

The Catechism specifies that God permits evil while respecting the freedom of His creature, and that He mysteriously knows how to draw good from it (CCC 311; cf. 324).

The fall is therefore not a theological "verdict" on the intrinsic worth of Greek Orthodoxy. It is the consequence of a complex political, military, demographic and spiritual constellation, in which enter: the weakness of Latin aid, internal Byzantine divisions, rising Ottoman power, the mutual misunderstanding between Rome and Constantinople, and — no doubt — a certain spiritual discouragement after two centuries of losses. The Christian gaze is called to mourn the fall as a civilizational loss, without making it a polemical argument against Christian brethren.

Vatican II and the return to common memory

For five centuries, the Orthodox memory of 1453 and the Latin memory opposed each other. The liturgical rupture consummated at Hagia Sophia in December 1452, the rejected union of Florence, the Greek feeling of having been abandoned by the West, and symmetrically the Latin feeling of having seen the Greeks die rather than believe in pontifical primacy, durably froze dialogue.

The Second Vatican Council, in the decree Unitatis Redintegratio promulgated on 21 November 1964, effects a major reversal. The Council recognises in the Orthodox Churches sister Churches possessing authentic apostolic succession, valid sacraments and a liturgical life of full plenitude:

"Hence the special concern, characteristic of the Easterners, to preserve communion in faith and charity in the fraternal relations that must exist between the local Churches, as between sisters, has prevailed and still prevails among them." — Second Vatican Council, Unitatis Redintegratio, no. 14, 21 November 1964^[85]

On 7 December 1965, on the eve of the Council's close, Saint Paul VI and Ecumenical Patriarch Athenagoras I solemnly lift, by a common declaration read at Rome and at Constantinople on the same day, the mutual anathemas of 1054. For the first time in nine centuries, the two apostolic thrones publicly recognise each other as members of a Church seeking itself beyond its division^[86].

On 4 May 2001, at Athens, before Archbishop Christodoulos, Saint John Paul II asks God for forgiveness for the faults committed by Catholics against their Orthodox brethren, "by action or by omission", evoking — without pronouncing its date — the sack of the imperial city by the Latin crusaders (1204)^[87]. On 27 November 2004, receiving Ecumenical Patriarch Bartholomew I at Rome, he hands him the relics of Saint Gregory the Theologian and Saint John Chrysostom, carried off to Rome after 1204^[88]. These gestures concern the Latin sack of 1204, not the Ottoman fall of 1453: they do not erase the wound of 1453, but they show that Rome recognises its own faults in the common history.

This dynamic continues. On 30 November 2006, Benedict XVI travels in person to Constantinople (Istanbul) for the feast of Saint Andrew and takes part in the liturgy of Patriarch Bartholomew I at the Phanar. It is a visit laden with meaning: a Latin Pope enters the Greek patriarchal basilica, prays with the Eastern Patriarch, and publishes a common declaration on the path towards full communion^[89]. The fall of Constantinople, in today's Catholic heart, is not an argument of controversy: it is a common wound that Rome and Constantinople recognise together.

• The Crusades (1095–1291) — the hub article on the eight medieval crusades and their spiritual significance
• The First Crusade (1095–1099) — the specialised article on the crusade that takes Jerusalem and inaugurates the Latin-Orthodox relationship in the second millennium
• The Council of Florence (1438–1445) — the union of the Churches proclaimed then rejected
• Bartholomew I of Constantinople — the current Ecumenical Patriarch and the dialogue with Rome
• Unitatis Redintegratio — the conciliar decree on ecumenism (1964)
• The Baptism of Clovis — the other great royal anchor point of medieval Christendom