Editing Fall of Constantinople (section)

===European support===
[[List of Byzantine emperors|Byzantine Emperor]] [[Constantine XI]] swiftly understood Mehmed's true intentions and turned to [[Western Europe]] for help; but now the price of centuries of war and enmity between the [[Eastern Christianity|eastern]] and [[Western Christianity|western churches]] had to be paid. Since the [[East–West Schism|mutual excommunications]] of 1054, the [[Pope]] in Rome was committed to establishing authority over [[Eastern Orthodox Church|the eastern church]]. The union was agreed by the Byzantine Emperor [[Michael VIII Palaiologos]] in 1274, at the [[Second Council of Lyon]], and indeed, some Palaiologoi emperors had since been received into the [[Latin Church]]. Emperor [[John VIII Palaiologos]] had also recently negotiated union with [[Pope Eugene IV]], with the [[Council of Florence#Eugene IV's eastern strategy|Council of Florence]] of 1439 proclaiming a ''Bull of Union''. The imperial efforts to impose union were met with strong resistance in Constantinople. A [[Propaganda|propaganda initiative]] was stimulated by anti-unionist [[Greek Orthodox Church|Orthodox]] partisans in Constantinople; the population, as well as the laity and leadership of the Byzantine Church, became bitterly divided. Latent [[ethnic hatred]] between Greeks and Italians, stemming from the events of the [[Massacre of the Latins]] in 1182 by the Greeks and the [[Sack of Constantinople]] in 1204 by the Latins, played a significant role. Ultimately, the attempted union between east and west failed, greatly annoying [[Pope Nicholas V]] and the hierarchy of the Roman church.{{citation needed|date=January 2021}}

In the summer of 1452, when [[Rumelihisarı|Rumeli Hisarı]] was completed and the threat of the Ottomans had become imminent, Constantine wrote to the Pope, promising to implement the union, which was declared valid by a half-hearted imperial court on 12 December 1452.{{sfnp|Norwich|1997|p=373}} 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. Furthermore, these Western rulers did not have the wherewithal to contribute to the effort, especially in light of the weakened state of France and England from the [[Hundred Years' War]], Spain's involvement in the [[Reconquista]], the internecine fighting in the [[Holy Roman Empire]], and Hungary and Poland's defeat at the [[Battle of Varna]] of 1444. Although some troops did arrive from the mercantile city-states in northern 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. [[Isidore of Kiev|Cardinal Isidore]], funded by the Pope, arrived in 1452 with 200 archers.{{sfnp|Crowley|2005}} An accomplished soldier from [[Genoa]], [[Giovanni Giustiniani]], arrived in January 1453 with 400 men from Genoa and 300 men from Genoese [[Chios]].{{sfnp|Runciman|1965|pp=83–84}} As a specialist in defending walled cities, Giustiniani was immediately given the overall command of the defence of the land walls by the Emperor. The Byzantines knew him by the Latin spelling of his name, "John Justinian", named after the famous 6th century Byzantine emperor [[Justinian I|Justinian the Great]].<ref name="NewsIT">{{Cite web |date=29 May 2011 |title=Σαν σήμερα "έπεσε" η Κωσταντινούπολη |url=https://www.newsit.gr/ellada/san-simera-epese-i-kostantinoypoli/1973279/ |website=NewsIT |access-date=31 October 2020 |archive-date=26 March 2023 |archive-url=https://web.archive.org/web/20230326030150/https://www.newsit.gr/ellada/san-simera-epese-i-kostantinoypoli/1973279/ |url-status=live }}</ref> Around the same time, the captains of the Venetian ships that 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.{{sfnp|Runciman|1965|p=81}}
From the [[Kingdom of Naples|Kingdoms of Naples]] and [[Kingdom of Sicily|Sicily]] arrived in Constantinople the [[condottiero]] [[Gabriele Orsini del Balzo]], duke of [[Venosa]] and count of [[Ugento]], together with 200 Neapolitan archers, who died fighting for the defense of the capital of the Byzantine Empire.{{sfnp|Lilie|2005|p=464}}

Meanwhile, in Venice, deliberations were taking place concerning the kind of assistance the Republic would lend to Constantinople. The [[Venetian Senate|Senate]] decided upon sending a fleet in February 1453, but the fleet's departure was delayed until April, when it was already too late for ships to assist in battle.{{sfnp|Nicol|1993|p=}}{{page needed|date=June 2017}}{{sfnp|Runciman|1965|p=85}} Further undermining Byzantine morale, seven Italian ships with around 700 men, despite having sworn to defend Constantinople, slipped out of the capital the moment Giustiniani arrived. At the same time, Constantine's attempts to appease the Sultan with gifts ended with the execution of the Emperor's ambassadors.{{sfnp|Norwich|1997|p=373}}<ref name="ThackerayFindling2012" /><ref name="Norwich1998" /><ref name="Somerwil-Ayrton2007" /><ref name="Roberts1973" /><ref name="Brownworth2009" />{{sfnp|Norwich|1995|p=415}}

[[File:Walls of Constantinople.JPG|right|thumb|upright=1|Restored Walls of Constantinople]]
[[File:Haliç zinciri (2).jpg|thumb|right|upright=0.9|The [[boom (navigational barrier)|chain]] that closed off the entrance to the Golden Horn in 1453, now on display in the [[İstanbul Archaeology Museums]].]]