The Desperate Diplomacy of a Dying Empire

On Christmas Day 1400, King Henry IV of England hosted a banquet at his Eltham palace to welcome a most distinguished guest – Manuel II Palaiologos, Emperor of the Romans (as the Byzantine rulers still styled themselves). The irony was palpable: Britain, once a Roman province, now hosted its former sovereign who came as a supplicant. Manuel’s European tour through Italy and France had yielded only polite refusals, leaving England as his last hope. The English nobility marveled at the emperor’s dignified bearing and snow-white robes, but practical concerns prevailed. England, ravaged by the Black Death and locked in the Hundred Years’ War with France, could ill afford adventures in the East, especially after the disastrous Crusader defeat at Nicopolis in 1396 against the Ottoman Turks. As the English Chancellor Adam noted with melancholy: “How pitiful that such noble Christian princes are brought so low by the Saracens. Oh, where is the glory of ancient Rome?”

Manuel had little time for such nostalgic lamentations. Back in Constantinople, his nephew and co-emperor John VII desperately held the city against the siege of Ottoman Sultan Bayezid “the Thunderbolt,” who sought to fulfill the centuries-old Muslim dream of capturing the New Rome. Manuel’s diplomatic efforts secured only token support – a small French contingent under Marshal Boucicaut. By 1402, Bayezid delivered his ultimatum: surrender the city. John VII’s defiant reply echoed through history: “Tell your master we are weak in arms but strong in faith in God. Let the Sultan do as he pleases.”

The City of the World’s Desire

Founded by Constantine the Great in 324 AD, Constantinople had withstood 23 sieges over eleven centuries. Persians, Avars, Arabs, and Rus had all failed before its mighty walls. Only the perfidious Fourth Crusade in 1204 had breached its defenses, a trauma from which the empire never fully recovered. By the 15th century, the “Roman Empire” was a shadow of its former self – reduced to the capital and parts of the Peloponnese, its revenues a mere 2% of its medieval peak. Foreign travelers described its citizens as “ragged and malnourished.” The end seemed inevitable.

Yet divine providence intervened unexpectedly. As Bayezid besieged Constantinople, Timur (Tamerlane), the Turco-Mongol conqueror, demanded the Ottomans relinquish Byzantine territory. When Bayezid insulted Timur’s envoy, the Sultan abruptly lifted the siege to confront this new threat. The armies met at Ankara on July 25, 1402. Bayezid’s overconfidence and his army’s poor morale proved fatal. The Ottomans were routed, the Sultan captured (later dying in captivity), and his empire plunged into a decade-long civil war known as the Ottoman Interregnum.

This reprieve offered Byzantium a golden opportunity for revival. Manuel skillfully exploited the Ottoman collapse, reclaiming territories and playing rival claimants against each other. However, Europe remained indifferent. When Mehmed I finally reunified the Ottoman state in 1413, his friendly relations with Manuel provided temporary security. But this fragile peace collapsed in 1421 when Mehmed’s son Murad II, pressured by hawkish advisors, besieged Constantinople. The ancient walls held once more, and Murad, after suppressing rebellions, focused on rebuilding Ottoman power.

The Last Gamble: Church Union and the Crusade That Failed

In 1423, Manuel retired, succeeded by his son John VIII. Convinced only Western aid could save the empire, John pursued union with the Roman Catholic Church, despite his father’s warnings. The timing seemed propitious – the Council of Constance (1414-1418) had ended the Western Schism, and the new Pope Martin V owed his position to conciliarism. After lengthy negotiations, Pope Eugene IV invited Byzantine delegates to Italy. The Council opened in Ferrara in 1438 before moving to Florence in 1439.

The theological divisions ran deep after four centuries of schism since 1054. The Filioque clause, purgatory, papal supremacy, and Eucharistic practices all proved contentious. Despite Byzantine reservations, political desperation forced acceptance of union. Most Greek bishops signed, but the agreement sparked outrage back home. The populace, led by monk Gennadius Scholarius, rejected the “Latin heresy.” As Grand Duke Loukas Notaras famously declared: “Better the Sultan’s turban than the Cardinal’s hat.”

The union’s sole tangible result was a belated crusade. In 1444, a predominantly Hungarian army under John Hunyadi crossed the Danube, violating a recent truce. At Varna, the crusaders were annihilated by Murad II. This disaster marked Europe’s last serious attempt to save Byzantium.

The Young Conqueror and the Last Emperor

In 1448, John VIII died childless, succeeded by his brother Constantine XI, the ablest of Manuel’s ten sons. As Despot of Morea, Constantine had proven himself a capable soldier and administrator. His coronation in 1449 – the last in Byzantine history – occurred at Mistra rather than Constantinople, as the traditional venue, Hagia Sophia, was now deemed “contaminated” by the Union.

Constantine inherited a rump state: Constantinople and its suburbs, the Morea, and a few Aegean islands. The Ottoman Empire, now recovered from Timur’s blow, surrounded the city completely. When Murad died in 1451, his 19-year-old son Mehmed II ascended the throne. The new Sultan, humiliated by an earlier forced abdication, burned to prove himself. Constantine’s fatal miscalculation came when he demanded Mehmed continue payments for Orhan, a Ottoman pretender sheltered in Constantinople. This perceived threat likely decided Mehmed to eliminate Byzantium once and for all.

In 1452, Mehmed constructed Rumeli Hisarı (the “Throat-Cutter”) on the Bosporus’ European shore, completing the stranglehold on Constantinople’s supply lines. When Byzantine envoys protested, Mehmed imprisoned and executed them – war was inevitable.

The Siege Begins: David Against Goliath

On April 2, 1453, the Ottoman vanguard appeared before Constantinople’s walls. Emperor Constantine ordered the city gates sealed and the Golden Horn blocked by a massive chain. The defenders numbered barely 7,000 against Mehmed’s estimated 80,000. Key figures included:

– Giovanni Giustiniani Longo: A Genoese captain who arrived with 700 professional soldiers, appointed overall commander of the defenses.
– Loukas Notaras: Megas Doux (Grand Duke) and commander of the reserves.
– Cardinal Isidore: Papal legate who brought 200 archers from Rome.

The city’s legendary defenses centered on the triple Theodosian Walls – 5.6 km of concentric fortifications with 96 towers. The weakest point was the Mesoteichion section where the Lycus River passed under the walls. Constantine and Giustiniani concentrated their best troops here.

Mehmed’s secret weapon was Hungarian engineer Orban’s massive cannon, capable of hurling 1,200-pound stones. The bombardment began on April 6, systematically targeting the Mesoteichion. Each night, citizens worked desperately to repair the damage with wooden stockades and earth-filled barrels.

Naval Battles and Desperate Measures

On April 20, three Genoese and one Byzantine ship broke through the Ottoman blockade, boosting morale. In response, Mehmed executed his admiral Baltoghlu and conceived an audacious plan: transporting ships overland into the Golden Horn. On April 22, 70 vessels were hauled on greased logs behind Pera (Galata), bypassing the chain. A subsequent Christian night attack failed due to Genoese treachery.

By May, food shortages grew acute. On May 23, a ship returned from searching the Aegean – no Venetian relief fleet was found. Morale collapsed as prophecies seemed fulfilled: the empire would fall under an emperor Constantine born of a Helen (Constantine XI’s mother was Helena Dragaš). A procession with the Virgin’s icon slipped inexplicably, followed by unseasonal fog – signs interpreted as God abandoning the city.

The Final Assault

On May 28, Mehmed announced the decisive attack for the next day. That evening, Constantinople witnessed its last Christian unity – Orthodox and Catholic clergy held joint services in Hagia Sophia. Constantine delivered his moving final speech: “I urge you to fight like men with brave souls, as you have done from the beginning.” He then rode through the city, begging forgiveness from anyone he had wronged.

The assault began at midnight. Wave after wave attacked – first irregular bashi-bazouks, then Anatolian troops, finally the elite Janissaries. At dawn, a tragic mishap occurred: the Kerkoporta postern gate was left open, allowing Turks to enter and raise their flag. Simultaneously, Giustiniani was grievously wounded by gunfire. His Genoese troops panicked, creating chaos. Constantine, with his Spanish cousin Don Francisco and aide John Dalmata, made a last stand at the breach before disappearing into the melee.

By midday, the city was lost. The Turks poured in, slaughtering and enslaving. Hagia Sophia became a mosque that same afternoon. Mehmed, entering the desolate Great Palace, quoted a Persian poet: “The spider weaves his web in the palace of the Caesars; the owl calls the watches in the towers of Afrasiab.”

Aftermath and Legacy

Constantine XI’s body was never conclusively identified, spawning legends that he sleeps beneath the Golden Gate, awaiting Constantinople’s liberation. Mehmed, now “Caesar of Rome,” showed remarkable statesmanship: he appointed Gennadius Scholarius as Orthodox Patriarch, granting religious autonomy to the Greeks. Notaras and other nobles were executed, but the city was repopulated with peoples from across the empire.

The fall reverberated throughout Christendom. Russia claimed the mantle of the “Third Rome,” while Western Europe lamented the loss yet did little. The Ottoman Empire, now unquestionably a world power, would threaten Europe for centuries. Constantinople’s conquest completed Islam’s long quest for the “Red Apple” – the ultimate symbol of worldly dominion.

In the end, Byzantium’s demise resulted from structural weaknesses: territorial and economic decline, the 1204 disaster, and failure to adapt militarily. Yet its 1,123-year endurance remains unparalleled. As historian Steven Runciman noted: “There was no other like it… It was the Roman Empire, the eternal empire to which there could be no end.” Its legacy endures in law, art, and the very idea of civilization’s continuity through dark times. The phoenix of Byzantium may have fallen, but its ashes still glow in the modern world.