Fall of Constantinople The Fall of Constantinople ( ; , " " ) was the capture of Constantinople , the capital of the Eastern Roman ( Byzantine ) Empire , which occurred after a siege by the invading Ottoman Empire , under the command of 21 - year - old Ottoman Sultan Mehmed II , against the defending army commanded by Byzantine Emperor Constantine XI Palaiologos . The siege lasted from Friday , 6 April 1453 until Tuesday , 29 May 1453 ( according to the Julian calendar ) , when the city fell and was finally conquered by the Ottomans . The capture of Constantinople ( and two other Byzantine splinter territories soon thereafter ) marked the end of the Roman Empire , an imperial state which had lasted for nearly 1 , 500 years . The Ottoman conquest of Constantinople also dealt a massive blow to Christendom , as the Ottoman armies thereafter were free to advance into Europe without an adversary to their rear . After the conquest , Sultan Mehmed transferred the capital of the Ottoman Empire from Adrianople to Constantinople . Several Greek and non - Greek intellectuals fled the city before and after the siege , with the majority of them migrating particularly to Italy , which helped fuel the Renaissance . The conquest of the city of Constantinople and the end of the Byzantine Empire marks , for some historians , the end of the Middle Ages . State of the Byzantine Empire . Constantinople had been an imperial capital since its consecration in 330 under Roman Emperor Constantine the Great . In the following eleven centuries , the city had been besieged many times but was captured only once : during the Fourth Crusade in 1204 . The crusaders established an unstable Latin state in and around Constantinople while the remaining empire splintered into a number of Greek successor states , notably Nicaea , Epirus and Trebizond . These Greeks fought as allies against the Latin establishments but among themselves for return to the Byzantine throne . The Nicaeans reconquered Constantinople from the Latins in 1261 . Thereafter was little peace for the much - weakened empire ; it continually fended off attacks from the Latins , the Serbians , the Bulgarians and , most importantly , the Ottoman Turks . By 1450 the empire was exhausted , consisting of a few square miles outside the city of Constantinople itself , the Princes ' Islands in the Sea of Marmara , and the Peloponnese with its cultural center at Mystras . The Empire of Trebizond , an independent successor state that formed in the aftermath of the Fourth Crusade , also survived on the coast of the Black Sea . Preparations . When Sultan Mehmed II succeeded his father in 1451 , it was widely believed that the young ruler , then 19 years old , would prove incapable — and that he would pose no great threat to Christian possessions in the Balkans and the Aegean . This optimism was reinforced by friendly assurances made by Mehmed to envoys sent to his new court . But Mehmed ' s actions spoke louder than his mild words . Beginning early in 1452 he built a second Ottoman fortress , named " Rumeli Hisarı " , on the Bosphorus ; this was done on the European side several miles north of Constantinople , and set directly across the strait from the similar fortress " Anadolu Hisarı " , which his great grandfather Bayezid I had previously built on the Asian side . This fortress - pair gained for the Turks complete control of sea traffic on the Bosphorus ; specifically , it prevented help from the north , the Genoese colonies on the Black Sea coast , from reaching Constantinople . ( The new fortress was also known as " Boğazkesen " , which held the dual meanings ' strait - blocker ' or ' throat - cutter ' , emphasizing its strategic position . ) In October 1452 , Mehmed ordered Turakhan Beg to lead a large force into the Peloponnese and remain there to keep the despots Thomas and Demetrios from assisting their brother Constantine during the impending siege of Constantinople . Byzantine Emperor Constantine XI understood Mehmed ' s intentions , and turned to western Europe for help ; but now the fruits of centuries of war and enmity between the eastern and western churches would be tolled . Since the mutual excommunications of 1054 , the Pope in Rome was committed to imposing dominion over the eastern church . Nominal union had been negotiated in 1274 , ( at Lyon ) , and indeed , some Palaiologoi emperors ( Latin , Palaeologan ) had since been received into the Latin church . And , Emperor John VIII Palaiologos had recently negotiated union with Pope Eugene IV , with the Council of Florence of 1439 proclaiming a " Bull of Union " . These events , however , stimulated a massive propaganda initiative by anti - unionist partisans in Constantinople ; and the population as well as the laity and leadership of the Byzantine Church became bitterly divided . Latent ethnic hatred s between Greeks and Italians — stemming from the events of the sack of Constantinople in 1204 by the Latins — played a significant role . Finally , the " Union " failed , greatly annoying Pope Nicholas V and the hierarchy of the Roman church . In the summer of 1452 , when Rumeli Hisari was completed and the threat had become imminent , Constantine wrote to the Pope , promising to implement the Union , which was declared valid by a half - hearted imperial court on Tuesday 12 December 1452 . Although he was eager for an advantage , Pope Nicholas V did not have the influence the Byzantines thought he had over the Western Kings and Princes , some of whom were wary of increasing Papal control , and these had not the wherewithal to contribute to the effort , especially in light of the weakened state of France and England from the Hundred Years ' War , Spain being in the final part of the Reconquista , the internecine fighting in the German Principalities , and Hungary and Poland ' s defeat at the Battle of Varna of 1444 . Although some troops did arrive from the mercantile city states in the north of Italy , the Western contribution was not adequate to counterbalance Ottoman strength . Some Western individuals , however , came to help defend the city on their own account . One of these was an accomplished soldier from Genoa , Giovanni Giustiniani , who arrived with 700 armed men in January 1453 . A specialist in defending walled cities , he was immediately given the overall command of the defense of the land walls by the emperor . Around the same time , the captains of the Venetian ships which happened to be present in the Golden Horn offered their services to the Emperor , barring contrary orders from Venice , and Pope Nicholas undertook to send three ships laden with provisions , which set sail near the end of March . In Venice , meanwhile , deliberations were taking place concerning the kind of assistance the Republic would lend to Constantinople . The Senate decided upon sending a fleet , but there were delays , and when it finally set out late in April , it was already too late for it to be able to take part in the battle . Further undermining Byzantine morale , seven Italian ships with around 700 men slipped out of the capital at the moment when Giustiniani arrived , men who had sworn to defend the capital . At the same time , Constantine ' s attempts to appease the Sultan with gifts ended with the execution of the Emperor ' s ambassadors — even Byzantine diplomacy could not save the city . Fearing a possible naval attack along the shores of the Golden Horn , Emperor Constantine XI ordered that a defensive chain be placed at the mouth of the harbour . This chain , which floated on wooden logs , was strong enough to prevent any Turkish ship from entering the harbour . This device was one of two which gave the Byzantines some hope of extending the siege until the possible arrival of foreign help . This strategy was enforced because in 1204 the armies of the 4th Crusade successfully circumvented Constantinople ' s land defenses by breaching the Golden Horn Wall . Another strategy employed by the Byzantines was the repair and fortification of the Land Wall ( Theodosian Walls ) . Emperor Constantine deemed it necessary to ensure that the Blachernae district ' s wall were the most fortified because that section of the wall protruded northwards . The land fortifications comprised a wide moat fronting inner and outer crenellated walls studded with towers every 50 – 60 yards . Strength . The army defending Constantinople was relatively small ; it totalled about 7 , 000 men , 2 , 000 of whom were foreigners . At the onset of the siege probably 50 , 000 people were living within the walls , including the refugees from the surrounding area . Turkish commander Dorgano , who was in Constantinople in the pay of the Emperor , was also guarding one of the quarters of the city on the seaward side with the Turks in his pay . These Turks kept loyal to the Emperor and perished in the ensuing battle . The Ottomans , on the other hand , had a larger force . Recent studies and Ottoman archival data point out that there were about 50 , 000 - 80 , 000 Ottoman soldiers including between 5 , 000 and 10 , 000 Janissaries , an elite infantry corps , and thousands of Christian troops , notably 1 , 500 Serbian cavalry that the Serbian lord Đurađ Branković supplied as part of his obligation to the Ottoman sultan . But just a few months before , he had supplied the money for the reconstruction of the walls of Constantinople . Contemporaneous Western witnesses of the siege , who tend to exaggerate the military power of the Sultan , provide disparate and higher numbers ranging from 160 , 000 to 200 , 000 and to 300 , 000 ( Niccolò Barbaro : 160 , 000 ; the Florentine merchant Jacopo Tedaldi and the Great Logothete George Sphrantzes : 200 , 000 ; the Cardinal Isidore of Kiev and the Archbishop of Mytilene Leonardo di Chio : 300 , 000 ) . Ottoman dispositions and strategies . Mehmed built a fleet to besiege the city from the sea ( partially manned by Greek sailors from Gallipoli ) . Contemporary estimates of the strength of the Ottoman fleet span between about 100 ships ( Tedaldi ) , 145 ( Barbaro ) , 160 ( Ubertino Pusculo ) , 200 – 250 ( Isidore of Kiev , Leonardo di Chio ) to 430 ( Sphrantzes ) . A more realistic modern estimate predicts a fleet strength of 126 ships , specifically composed of 6 large galleys , 10 ordinary galleys , 15 smaller galleys , 75 large rowing boats , and 20 horse - transports . Before the siege of Constantinople , it was known that the Ottomans had the ability to cast medium - sized cannons , but the range of some pieces they were able to field far surpassed the defenders ' expectations . Instrumental to this Ottoman advancement in arms production was a somewhat mysterious figure by the name of Orban ( Urban ) , a Hungarian ( though some suggest he was German ) . One cannon designed by Orban was named " Basilica " and was long , and able to hurl a 600 lb ( 272 kg ) stone ball over a mile ( 1 . 6 km ) . The master founder initially tried to sell his services to the Byzantines , who were unable to secure the funds needed to hire him . Orban then left Constantinople and approached Mehmed II , claiming that his weapon could blast ' the walls of Babylon itself ' . Given abundant funds and materials , the Hungarian engineer built the gun within three months at Adrianople , from which it was dragged by sixty ox en to Constantinople . In the meantime , Orban also produced other cannons instrumental for the Turkish siege forces . Orban ' s cannon had several drawbacks however : it took three hours to reload ; cannonballs were in very short supply ; and the cannon is said to have collapsed under its own recoil after six weeks ( this fact however is disputed , being reported only in the letter of Archbishop Leonardo di Chio and in the later and often unreliable Russian chronicle of Nestor Iskander ) . Having previously established a large foundry about away , Mehmed now had to undergo the painstaking process of transporting his massive artillery pieces . Orban ' s giant cannon was said to have been accompanied by a crew of 60 oxen and over 400 men . Mehmed planned to attack the Theodosian Walls , the intricate series of walls and ditches protecting Constantinople from an attack from the West , the only part of the city not surrounded by water . His army encamped outside the city on the Monday after Easter , 2 April 1453 . The bulk of the Ottoman army were encamped south of the Golden Horn . The regular European troops , stretched out along the entire length of the walls , were commanded by Karadja Pasha . The regular troops from Anatolia under Ishak Pasha were stationed south of the Lycus down to the Sea of Marmara . Mehmed himself erected his red - and - gold tent near the " Mesoteichion " , where the guns and the elite regiments , the Janissaries , were positioned . The Bashi - bazouk s were spread out behind the front lines . Other troops under Zagan Pasha were employed north of the Golden Horn . Communication was maintained by a road that had been constructed over the marshy head of the Horn . Byzantine dispositions and strategies . The city had about 20 km of walls ( Theodosian Walls : 5 . 5 km ; sea walls along the Golden Horn : 7 km ; sea walls along the Sea of Marmara : 7 . 5 km ) , one of the strongest sets of fortified walls in existence at the time . The walls had recently been repaired ( under John VIII ) and were in fairly good shape , giving the defenders sufficient reason to believe that they could hold out until help from the West arrived . In addition , the defenders were relatively well - equipped with a fleet of 26 ships : 5 from Genoa , 5 from Venice , 3 from Venetian Crete , 1 from Ancona , 1 from Aragon , 1 from France , and about 10 Byzantine . On 5 April , as the Sultan himself arrived with his last troops , the defenders took up their positions . As their numbers were insufficient to occupy the walls in their entirety , it had been decided that only the outer walls would be manned . Constantine and his Greek troops guarded the " Mesoteichion " , the middle section of the land walls , where they were crossed by the river Lycus . This section was considered the weakest spot in the walls and an attack was feared here most . Giustiniani was stationed to the north of the emperor , at the Charisian Gate ( " Myriandrion " ) ; later during the siege , he was shifted to the " Mesoteichion " to join Constantine , leaving the " Myriandrion " to the charge of the Bocchiardi brothers . Minotto and his Venetians were stationed in the Blachernae palace , together with Teodoro Caristo , the Langasco brothers , and Archbishop Leonardo of Chios . To the left of the emperor , further south , were the commanders Cataneo , with Genoese troops , and Theophilus Palaeologus , who guarded the Pegae Gate with Greek soldiers . The section of the land walls from the Pegae Gate to the Golden Gate ( itself guarded by a certain Genoese called Manuel ) was defended by the Venetian Filippo Contarini , while Demetrius Cantacuzenus had taken position on the southernmost part of the Theodosian wall . The sea walls were manned more sparsely , with Jacobo Contarini at Stoudion , a makeshift defense force of Greek monks to his left hand , and prince Orhan at the Harbour of Eleutherius . Pere Julià was stationed at the Great Palace with Genoese and Catalan troops ; Cardinal Isidore of Kiev guarded the tip of the peninsula near the boom . The sea walls at the southern shore of the Golden Horn were defended by Venetian and Genoese sailors under Gabriele Trevisano . Two tactical reserves were kept behind in the city , one in the Petra district just behind the land walls and one near the Church of the Holy Apostles , under the command of Loukas Notaras and Nicephorus Palaeologus , respectively . The Venetian Alviso Diedo commanded the ships in the harbor . Although the Byzantines also had cannons , they were much smaller than those of the Ottomans and the recoil tended to damage their own walls . According to David Nicolle ( 2000 ) , despite many odds , the idea that Constantinople was inevitably doomed is wrong , and the overall situation was not as one - sided as a simple glance at a map might suggest . It has also been claimed that Constantinople was " the best - defended city in Europe " at that time . Siege . At the beginning of the siege , Mehmed sent out some of his best troops to reduce the remaining Byzantine strongholds outside the city of Constantinople . The fortress of Therapia on the Bosphorus and a smaller castle at the village of Studius near the Sea of Marmara were taken within a few days . The Princes ' Islands in the Sea of Marmara were taken by Admiral Baltoghlu ' s fleet . Mehmed ' s massive cannon fired on the walls for weeks , but due to its imprecision and extremely slow rate of reloading the Byzantines were able to repair most of the damage after each shot , limiting the cannon ' s effect . Meanwhile , despite some probing attacks , the Ottoman fleet under Suleiman Baltoghlu could not enter the Golden Horn due to the defensive chain the Byzantines had laid across the entrance . Although one of the fleet ' s main tasks was to prevent any ships from outside from entering the Golden Horn , on 20 April a small flotilla of four Christian ships managed to slip in after some heavy fighting , an event which strengthened the morale of the defenders and caused embarrassment to the Sultan . Baltoghlu ' s life was spared after his subordinates testified to his bravery during the conflict . After that , Mehmed tried to circumvent the chain . He ordered the construction of a road of greased logs across Galata on the north side of the Golden Horn , and rolled his ships across on 22 April . This seriously threatened the flow of supplies from Genovese ships from the — nominally neutral — colony of Pera , and demoralized the Byzantine defenders . On the night of 28 April , an attempt was made to destroy the Ottoman ships already in the Golden Horn using fire ship s , but the Ottomans had been warned in advance and forced the Christians to retreat with heavy losses . From then on , the defenders were forced to disperse part of their forces to the Golden Horn walls , causing defense in other sections of the walls to weaken . On 29 April 260 Ottoman prisoners were beheaded on the walls before the eyes of the Ottomans . The Turks had made several frontal assaults on the land wall , but were always repelled with heavy losses . Venetian surgeon Niccolò Barbaro , describing in his diary one of such frequent land attacks especially by the Janissaries , wrote : After these inconclusive frontal offensives , the Ottomans sought to break through the walls by constructing underground tunnels in an effort to mine them from mid - May to 25 May . Many of the sappers were miners of German origin sent from Novo Brdo by the Serbian despot . They were placed under the command of Zagan Pasha . However , the Byzantines employed an engineer named Johannes Grant ( who was said to be German but was probably Scottish ) , who had counter - mines dug , allowing Byzantine troops to enter the mines and kill the Turkish workers . The Byzantines intercepted the first Serbian tunnel on the night of 16 May . Subsequent tunnels were interrupted on 21 , 23 , and 25 May , and destroyed with Greek fire and vigorous combat . On 23 May , the Byzantines captured and tortured two Turkish officers , who revealed the location of all the Turkish tunnels , which were then destroyed . On 21 May , Mehmed sent an ambassador to Constantinople and offered to lift the siege if they gave him the city . He promised he would allow the Emperor and any other inhabitant to leave with their possessions . Moreover , he would recognise the Emperor as governor of the Peloponese . Lastly , he guaranteed the safety of the population that would remain in the city . Constantine XI accepted to pay higher tributes to the sultan and recognized the status of all the conquered castles and lands in the hands of the Turks as Ottoman possession . However , regarding Constantinople , he stated : Around this time , Mehmed had a final council with his senior officers . Here he encountered some resistance ; one of his Viziers , the veteran Halil Pasha , who had always disapproved of Mehmed ' s plans to conquer the city , now admonished him to abandon the siege in the face of recent adversity . Halil was overruled by Zagan Pasha , who insisted on an immediate attack . Having been accused of bribery , Halil Pasha was put to death later that year . Mehmed planned to overpower the walls by sheer force , expecting that the weakened Byzantine defense by the prolonged siege would now be worn out before he ran out of troops and started preparations for a final all - out offensive . Final assault . Preparations for the final assault were started in the evening of 26 May and continued to the next day . For 36 hours after the war council decision to attack , the Ottomans extensively mobilized their manpower in order to prepare for the general offensive . Prayer and resting would be then granted to the soldiers on the 28th , and then the final assault would be launched . On the Byzantine side , a small Venetian fleet of 12 ships , after having searched the Aegean , reached the Capital on 27 May and reported to the Emperor that no large Venetian relief fleet was on its way . On 28 May , as the Ottoman army prepared for the final assault , large - scale religious processions were held in the city . In the evening a last solemn ceremony was held in the Hagia Sophia , in which the Emperor and representatives of both the Latin and Greek church partook , together with nobility from both sides . Shortly after midnight on 29 May the all - out offensive began . The Christian troops of the Ottoman Empire attacked first , followed by the successive waves of the irregular azap s , who were poorly trained and equipped , and Anatolians who focused on a section of the Blachernae walls in the northwest part of the city , which had been damaged by the cannon . This section of the walls had been built earlier , in the eleventh century , and was much weaker . The Anatolians managed to breach this section of walls and entered the city but were just as quickly pushed back by the defenders . Finally , as the battle was continuing , the last wave , consisting of elite Janissaries , attacked the city walls . The Genoese general in charge of the land troops , Giovanni Giustiniani , was grievously wounded during the attack , and his evacuation from the ramparts caused a panic in the ranks of the defenders . Giustiniani was carried to Chios , where he succumbed to his wounds a few days later . With Giustiniani ’ s Genoese troops retreating into the city and towards the harbor , Constantine and his men , now left to their own devices , kept fighting and managed to hold off the Janissaries for a while , but eventually they could not stop them from entering the city . The defenders were also being overwhelmed at several points in Constantine ’ s section . When Turkish flags were seen flying above a small postern gate , the Kerkoporta , which was left open , panic ensued , and the defense collapsed , as Janissary soldiers , led by Ulubatlı Hasan pressed forward . It is said that Constantine , throwing aside his purple regalia , led the final charge against the incoming Ottomans , dying in the ensuing battle in the streets like his soldiers . On the other hand Nicolò Barbaro , a Venetian eyewitness to the siege , wrote in his diary that it was said that Constantine hanged himself at the moment when the Turks broke in at the San Romano gate , although his ultimate fate remains unknown . After the initial assault , the Ottoman Army fanned out along the main thoroughfare of the city , the Mese , past the great forums , and past the Church of the Holy Apostles , which Mehmed II wanted to provide a seat for his newly appointed patriarch which would help him better control his Christian subjects . Mehmed II had sent an advance guard to protect key buildings such as the Holy Apostles , as he did not wish to establish his new capital in a thoroughly devastated city . The Army converged upon the Augusteum , the vast square that fronted the great church of Hagia Sophia whose bronze gates were barred by a huge throng of civilians inside the building , hoping for divine protection . After the doors were breached , the troops separated the congregation according to what price they might bring in the slave markets . Mehmed II allowed his troops to plunder the city for three days as it was customary . Soldiers fought over the possession of some of the spoils of war . According to the Venetian surgeon Nicolò Barbaro " all through the day the Turks made a great slaughter of Christians through the city " . According to Philip Mansel thousands of civilians were killed and 30 , 000 civilians were enslaved or deported . Ottoman casualties are unknown but they are believed by most historians to be very heavy due to several unsuccessful Ottoman attacks made during the siege and final assault . Barbaro described blood flowing in the city " like rainwater in the gutters after a sudden storm " , and bodies of the Turks and Christians floating in the sea " like melons along a canal " . Aftermath . On the third day of the conquest , Mehmed II ordered all looting to stop and sent his troops back outside the city walls . Byzantine historian George Sphrantzes , an eyewitness to the fall of Constantinople , described the Sultan ' s actions : Hagia Sophia was converted into a mosque , but the Greek Orthodox Church remained intact , and Gennadius Scholarius was appointed Patriarch of Constantinople . The Morean ( Peloponnesian ) fortress of Mystras , where Constantine ' s brothers Thomas and Demetrius ruled , constantly in conflict with each other and knowing that Mehmed would eventually invade them as well , held out until 1460 . Long before the fall of Constantinople , Demetrius had fought for the throne with Thomas , Constantine , and their other brothers John and Theodore . Thomas escaped to Rome when the Ottomans invaded Morea while Demetrius expected to rule a puppet state , but instead was imprisoned and remained there for the rest of his life . In Rome , Thomas and his family received some monetary support from the Pope and other Western rulers as Byzantine emperor in exile , until 1503 . In 1461 the independent Byzantine state in Trebizond fell to Mehmed . With the capture of Constantinople , Mehmed II had acquired the " natural " capital of its kingdom , albeit one in decline due to years of war . And the conquest of the Byzantine Empire removed a foe to the rear of the Ottoman advance into Europe . The loss of the city was a great blow to Christendom , and it exposed the Christian west to a vigorous and aggressive foe in the east . Pope Nicholas V called for an immediate counter - attack in the form of a crusade . When no European monarch was willing to lead the crusade , the Pope himself decided to go , but his early death stopped this plan . For some time Greek scholars had gone to Italian city - states , a cultural exchange begun in 1396 by Coluccio Salutati , chancellor of Florence , who had invited Manuel Chrysoloras , a Byzantine scholar to lecture at the University of Florence . After the conquest many Greeks , such as John Argyropoulos and Constantine Lascaris , fled the city and found refuge in the Latin West , bringing with them knowledge and documents from the Greco - Roman tradition to Italy and other regions that further propelled the Renaissance . Those Greeks who stayed behind in Constantinople mostly lived in the Phanar and Galata districts of the city . The Phanariotes , as they were called , provided many capable advisers to the Ottoman rulers . Scholars consider the Fall of Constantinople as a key event ending the Middle Ages and starting the Renaissance because of the end of the old religious order in Europe and the use of cannon and gunpowder . The fall of Constantinople and general encroachment of the Turks in that region also severed the main overland trade link between Europe and Asia , and as a result more Europeans began to seriously consider the possibility of reaching Asia by sea . Third Rome . Byzantium is a term used by modern historians to refer to the later Roman Empire . In its time , the Empire ruled from Constantinople ( or " New Rome " as Constantine had officially named it ) was considered simply " the Roman Empire . " The fall of Constantinople led competing factions to lay claim to being the inheritors of the Imperial mantle . Russian claims to Byzantine heritage clashed with those of the Ottoman Empire ' s own claim . In Mehmed ' s view , he was the successor to the Roman Emperor , declaring himself " Kayser - i Rum " , literally " Caesar of Rome " , that is , of the Roman Empire , though he was remembered as " the Conqueror " , founder of a political system that survived until 1922 with the establishment of the Republic of Turkey that has since held Constantinople ( renamed Istanbul ) but moved the capital of the Turkish state to Ankara . Such conflict in ideology only stimulated warfare between the Russia n and Ottoman Empire , with the 18th and 19th century seeing Russian armies approach slowly closer to Constantinople . In fact the Russian armies came all the way to Yeşilköy suburb of Constantinople , which is only west of Topkapı Palace during the Russo - Turkish War of 1877 – 1878 . Stefan Dušan , Tsar of Serbia , and Ivan Alexander , Tsar of Bulgaria both made similar claims , regarding themselves as legitimate heirs to the Roman Empire . Other potential claimants , such as the Republic of Venice and the Holy Roman Empire have disintegrated into history . In addition to the military and political benefits bestowed upon the Turks with its capture , it also brought the trade in Eastern spices through Muslim intermediaries into a declining period . Europeans would continue to trade through Constantinople into the 16th century but high prices propelled the search for alternative sources of supply that did not pass through the intermediaries of the Ottomans and , to a lesser extent , the Safavids and Mamelukes . An increasing number of Portuguese , Spanish and Dutch ships began to attempt to sail to India via the southern tip of Africa . Indeed , had Columbus not believed that he would reach Asia to negotiate trade rights by sailing west — the mission as he presented it to his patron , the King of Spain — he would not have found the New World . Partial lunar eclipse . Medieval astronomers witnessed the May 1453 lunar eclipse , during which approximately two - thirds of the Moon was covered by the Earth ' s umbral shadow . The residual illumination the Moon during an eclipse , can often be red . This may explain why it is said a " red moon " took place during the eclipse , and was taken as an omen or prophecy of the city ' s transfer of power . Cultural references . Legends . There are many legends in Greece surrounding the Fall of Constantinople . It was said that the total lunar eclipse that occurred on 22 May 1453 , represented a fulfillment of a prophecy of the city ' s demise . Four days later , the whole city was blotted out by a thick fog , a condition unknown in that part of the world in May . When the fog lifted that evening , a strange light was seen playing about the dome of the Hagia Sophia , and from the city walls lights were seen in the countryside to the West , far behind the Turkish camp . The light around the dome was interpreted by some as the Holy Spirit departing from the Cathedral , while there was a distant hope that the lights were the campfires of the troops of John Hunyadi who had come to relieve the city . A more scientific theory postulates that the light was caused by the electrical weather phenomenon , St . Elmo ' s Fire . Another of them holds that two priests saying divine liturgy over the crowd disappeared into the cathedral ' s walls as the first Turkish soldiers entered . According to the legend , the priests will appear again on the day Constantinople returns to Christian hands . Another legend refers to the " Marble King " , Constantine XI , holding that , when the Ottomans entered the city , an angel rescued the emperor , turned him into marble and placed him in a cave under the earth near the Golden Gate , where he waits to be brought to life again ( a variant of the sleeping hero legend ) . Cultural impact . The Christian re - conquest of Constantinople remained a fascinating and much sought - after event in Western Europe for years to come after its fall to the House of Osman . Rumours of Constantine XI ' s survival and subsequent rescue by an angel led many to hope that the city would one day return to Christian hands . However , as Western Europe entered the 16th century , the age of Crusading began to come to an end . Initially , the fall of the city seemed to cause a stir of crusading zeal in the West , where , apart from religious sentiments , Renaissance humanism had for about a century been fueling an interest in the cultural and intellectual heritage of classical antiquity , and the role that Byzantium had played in preserving that heritage . The great humanist Aeneas Silvius lamented that with the fall of Constantinople " Homer and Plato have died a second death " . This utterance was not true for learning in the fallen city . In addition to this , refugees from Constantinople to Italy brought with them ancient texts that further inspired humanist investigation of ancient philosophy and esotericism , especially Platonic and Neo - Platonic thought . As Pope Pius II , the same Aeneas Silvius declared a crusade in 1459 for the recapture of Constantinople , but any genuine enthusiasm that existed was short - lived , and a crusade never came into effect . Guillaume Dufay composed several songs lamenting the fall of the Eastern church , and the duke of Burgundy , Philip the Good , avowed to take up arms against the Turks . However , as the growing Ottoman power from this date on coincided with the Protestant Reformation and subsequent Counter - Reformation , the recapture of Constantinople became an ever - distant dream . Even France , once a fervent participant of the Crusades , became an ally of the Ottomans . Nonetheless , depictions of Christian coalitions taking the city and of the late Emperor ' s resurrection by Leo the Wise persisted . In 17th century Russia , the Fall of Constantinople had a role in the fierce theological and political controversy between adherents and opponents of the reforms in the Russian Orthodox Church , carried out by Patriarch Nikon and intended to bring the Russian Church closer to the norms and practices of other Orthodox churches . Avvakum and other of the " Old Believers " saw these reforms as a corruption of the Russian Church , which they considered to be the " true " Church of God . As the other Churches were more closely related to Constantinople in their liturgies , Avvakum argued that Constantinople fell to the Turks because of these heretical beliefs and practices . Impact on the Renaissance . The migration waves of Byzantine scholars and émigrés in the period following the sacking of Constantinople and the fall of Constantinople in 1453 , is considered by many scholars key to the revival of Greek and Roman studies that led to the development of the Renaissance humanism and science . These émigrés were grammarians , humanists , poets , writers , printers , lecturers , musicians , astronomers , architects , academics , artists , scribes , philosophers , scientists , politicians and theologians . They brought to Western Europe the far greater preserved and accumulated knowledge of their own ( Greek ) civilization . Megali idea . Between 1919 and 1922 , Greek politician Eleftherios Venizelos attempted to implement the Megali Idea ( recapture of Constantinople from the Ottoman Empire ) in the Greco - Turkish War ( 1919 - 1922 ) since the Ottoman Empire was severely weakened by its defeat in World War I and by the occupation of Constantinople by the British and French . However , in the course of the war Venizelos lost the election of 1920 and went into exile and Greece was defeated in the war by Turkey . The Ottoman Empire was replaced by the Turkish republic in 1922 . Renaming of the city . It is widely believed that the city was renamed to " Istanbul " in the aftermath of the conquest . In actuality , Ottomans used the Arabic transliteration of the city ' s name , " Kostantiniyye , " as can be seen in numerous Ottoman documents . The name of Istanbul , deriving from a Greek phrase ( " to the City " , Greek : eis - tin - polin ) was already spread among the Turkish populace of the Ottoman Empire before the conquest . Only in 1930 would Istanbul become the official name of the city by the revised Turkish Postal Law as part of Atatürk ' s reforms .