On the 29th of May, 1453, Constantinople fell to the Ottoman Turks led by the sultan Mehmet II, the Conqueror. In the predawn, the walls of the fortress-city that had defied barbarian attacks for a thousand years were still unscaled, albeit battered by Turkish artillery. After seven weeks of siege the mood of the City was bleakly fatalistic. Its defenders were no more than 7,000, and they confronted a multinational force of 100,000 marshaled by the sultan: elite Janissaries, Anatolian Turks, and mercenary irregulars from Italy, Greece, Hungary, and the Slavic countries (many Christian), sent first into battle and hemmed in by military police.
Almost until the last hour it might have gone differently. News that a Venetian fleet was coming to Byzantium’s aid had unsettled Mehmet’s court—it was rumored already to be on the island of Chios. A papal league was forming to mount a new crusade, and the Turk’s armistice with the Hungarians was about to expire. On May 23rd, Mehmet, a headstrong youth of 21, sent an emissary—the son of a Greek renegade, as it happened—to the emperor Constantine XI Paleologus with an offer to lift the siege in exchange for an enormous annual tribute of 100,000 gold bezants, which he must have known was beyond the Empire’s means. Alternatively, upon surrender its remaining citizens would be spared to depart the City with their portable belongings, and the emperor himself was guaranteed safe passage to exile and a reduced domain in the Peloponnesus—all conditions that Constantine had no reason to believe Mehmet would actually honor. For his part the emperor offered to surrender everything he possessed except for Constantinople, which, Steven Runciman reminds us, was by this point the only thing he did possess. In that case, the sultan replied, the alternatives for the Byzantines were surrender, the sword, or conversion.
This was the last negotiation. Yet, Mehmet countenanced the semblance of a debate in his inner council between his elderly vizier, Halil Pasha, who had always disapproved of the campaign, and a charismatic firebrand, Zaganos Pasha, who embraced it. Zaganos deprecated the Venetian threat and reminded the sultan, as if it were necessary, that his paragon, Alexander the Great, had conquered half the world with a much smaller army than his. The verdict and the pessimistic Halil’s eventual execution for treason were foretold by Mehmet’s private resolve that he would sit on Byzantium’s throne or be buried beneath its walls.
At nightfall, May 28, Mehmet urged his vast army to return to their tents for rest and reflection. Disturbing the peace, a band of dervishes pounced on the camp to preach the advantages of martyrdom. “Yet Mohammed principally trusted to the efficacy of temporal and visible rewards,” notes Gibbon. “‘The city and the buildings are mine,’ said Mohammed, ‘but I resign to your valour the captives and the spoils, the treasures of gold and beauty; be rich and be happy.’”
In their last week of freedom the Greeks were beset with dismal omens, a mephitic fog and a partial lunar eclipse among them. The moon was the City’s ancient symbol, and on the night of the 28th the moon was a crescent. After addressing the “noblest of the Greeks and the bravest of the allies,” Constantine and a privileged handful of his commanders took communion at Hagia Sophia, the Church of the Holy Wisdom, the vastest place of worship in Christendom, and probably in the world; the best he could do, writes Gibbon, was to arm them with the “courage of despair.” Later that night the first and last truly ecumenical Christian service was held in the great church; quoting a modern historian, Jason Goodwin: “and everyone came, Catalan and Orthodox Greek, schismatic bishops and the unionist cardinal, Catholic and Orthodox priests, and all the people who were not at the walls received communion from whoever chose to administer it, and made confession, to whoever was ready to hear it.”
The assault began at 01:30 in the morning, but without the usual frightful din of trumpets and kettle drums that announced a Turkish attack, leading some in the City to hope that it was simply a minor night attack. For seven weeks the siege of Constantinople unfolded. In the Golden Horn, Greeks and Turks engaged in a tight naval combat in which, for a long time, the Byzantines prevailed, showing their old cunning and armed with Greek fire (ancient napalm), but most crucially on the land walls. In both theaters Constantine’s strong right arm was a Genoese sailor and engineer, Giovanni Giustiniani Longo, a brave man of Ulyssean resourcefulness, who had brought with him 700 men in January; his particular expertise was the defense of walled cities, of which Constantinople was the greatest of all. Given charge of defending the fortifications, Giustiniani even contrived temporarily to disable the Turks’ biggest cannon, known as Urban, after its mercenary Hungarian designer. Giustiniani’s rising prestige and intimacy with the emperor aroused the enmity of Lucas Notaras, the Empire’s high admiral and megadux (grand duke), “whose ambition was not extinguished by the common danger”; he, the second man in Byzantium, and the Genoese hero indulged a feud in which, Gibbon notes, each accused the other of treachery and cowardice. Mehmet was envious of the emperor’s ingenious Italian. “What would I not give, to have that man in my service!”
The grand duke was also skeptical of Constantine’s loyal adherence to the union of the Greek and Latin churches that his brother John VIII Paleologus had negotiated; ratified at the Council of Florence in 1449, this desperate theological expedient was despised and ignored by his subjects, most emphatically the Latin services in St. Sophia. Or as Notaras quipped, unwisely, “Better the sultan’s turban than the cardinal’s hat.” Giustiniani was in the midst of the fighting at the Gate of St. Romanus when he was wounded by a Turkish bullet that penetrated his armor. According to Gibbon,
The immediate loss of Constantinople may be ascribed to the bullet, or arrow, which pierced the gauntlet of John Justiniani. The sight of his blood, and the exquisite pain, appalled the courage of the chief, whose arms and counsels were the firmest rampart of the city. As he withdrew from his station in quest of a surgeon, his flight was perceived and stopped by the indefatigable emperor. ‘Your wound,’ exclaimed Paleologus, ‘is slight; the danger is pressing; your presence is necessary; and whither will you retire?’—‘I will retire,’ said the trembling Genoese, ‘by the same road which God has opened to the Turks,’ and at these words he hastily passed through one of the breaches of the inner wall.
By a world-historical mischance (or was it merely that?), a little postern gate, which was said to have been forgotten by all except the old men, had been opened for a sortie, and not secured after. The Janissaries who tried the lock were surprised to find themselves pushing inside the city; routing the Greeks in the vicinity, they had raised Mehmet’s banner on the nearest towers. It was at this moment that Giustiniani was wounded. Close enough to witness the consternation caused by his ignoble retreat, Mehmet shouted, “The city is ours! It is ours already! See, there is no one left to defend it! Fear not! Follow me! The city is ours!”
The Empire had never recovered from the Fourth Crusade of 1204 when, rather than marching on to the Holy Land to battle the infidels, the crude nobility of the West (the counts of Flanders and the barons of France) allied with Venice to seize Constantinople from their fellow Christians. The Byzantines were, providentially for the plotters, embroiled in a typically complex dynastic struggle involving a titular emperor who was blind and in his dotage, a young pretender, a scheming courtier-turned-usurper, and a blinded boy prince languishing in prison. In the end the City was sacked; its citizens brutalized, hundreds of years of heaped-up treasures looted, with holy relics, of course, being the most sought after. The crude Baldwin of Flanders was proclaimed emperor, mounting the throne in looted regalia. Afterward, Greek princes maintained rival courts in Nicaea, Thessaloniki, Epirus, and Trebizon on the Black Sea; after fifty years the Latin usurpers were overthrown by Michael Paleologus, coming from Nicaea. With pitiful symbolism, as Steven Runciman epitomizes, “The last Latin Emperor in his extremity, after selling most of the relics to Saint Louis and before pawning his son and heir to the Venetians, had stripped the lead off all the roofs [of his palace] and disposed of them for cash.” After 1400 Constantinople was effectively encircled by the Turks, and would have come under their rule fifty years earlier if the world-shaking Tamerlane had not distracted—and almost destroyed—them at the battle of Ankara in 1402, where he captured the sultan Bayezit I, subsequently confining him in an iron cage; his vast pointless empire fell apart after his death, which came even as he was advancing an invasion of China.
In Byzantium, where once foreign visitors had wondered at the crowded opulence, Spanish or Arab tourists in the mid-14th and 15th century were struck by the emptiness and dereliction. Whole districts of the City had contracted into little walled towns. Elegant waterside villas, rich monasteries, shopping centers or luxury-goods manufacturers had vanished, replaced by hovels and overgrown countryside, untended hedgerows, bramble, wild roses. In the abandoned Hippodrome, where for centuries the Greens and Blues had cheered their teams’ charioteers and periodically convulsed the City with their rivalry, young aristos played polo in a vast weedy field.
Constantinople went through the motions of Empire, but the jewels in the imperial diadems were glass or paste. Its trade and even its politics were dominated by foreign traders who battened on concessions: A century before it fell to the Turks, Gibbon writes, the Roman Empire was close to becoming a province of Genoa. In the end Byzantium’s glories were artistic and intellectual: Aeneas Sylvius Piccolomini, who became Pope Pius II, wrote that in his day any Italian with scholarly pretensions would claim to have studied at the University of Constantinople. For all its decrepitude, the City, as a place and a polity, retained its imperial mystique, commanded as ever a superb physical situation, and would always have its geopolitical centrality as the gateway to the East and the hinge between Europe and Asia. When tempted with other riches, Mehmet insisted that the City was all he wanted.
The afternoon of May 29 found defeated allies, mostly Italian, swimming desperately to the Venetian and Genoese ships in the harbor. Turkish sailors marauded in the warehouses at the Golden Horn until they encountered and waylaid a little saint’s day procession consisting mostly of old women and a few old men, slaughtering the latter, and capturing the rest. It was a prelude to the mass looting and rapine which went on for most of the day. Of the last Byzantines, Cristopolos, a Greek renegade in the sultan’s service, recalled: “And some were massacred in their houses where they tried to hide, and some in churches where they sought refuge”; they suffered “stealing, disrobing, pillaging, raping, taking captive men, women, children, old men, young men, monks, priests, people of all sorts and conditions,” writes Gibbon, who expatiates on how fear and resignation had reduced the Byzantines to something like “a herd of timid animals.” Instinctively, from all the quarters they poured into St. Sophia, which was filled in an hour from the galleries to the nave, hopeful that the holiest of churches would protect them. They had always been a superstitious people, convinced that their City’s days were literally numbered with the reigns of all the emperors inscribed on occulted stones. Some of them, at least, were inclined to an invented tradition, “the prophecy of an enthusiast or imposter,” which had it that when the day came that Turks would invade the city, they would get no farther than Constantine’s column in the square facing St. Sophia: for an angel from heaven would deliver a sword to an ordinary man who would send the affrighted Turks flying, out of the West down to the East all the way to Persia. While the Byzantines expected the appearance of the “tardy angel,” the Turks axed through the cathedral’s locked bronze doors and began claiming what they had been promised, human and material, soldiers advancing on the altar in an iconoclastic fury, using their axes to destroy the sacred iconostasis where, just half a day before, the last emperor and his liegemen had prayed.
Gibbon: “Youth, beauty, and appearance of wealth, attracted their choice… In the space of an hour the male captives were bound with cords, the females with their veils and girdles. The senators were linked with their slaves; the prelates with the porters of the church; and the young men of a plebeian class with noble maids whose faces had been invisible to the sun and their nearest kindred.” But this rough democracy didn’t last. Soon enough, things were sorted out to the Conquerors’ satisfaction, as William Holton Hutton, later Dean of Winchester, dispassionately noted in 1900: “The usual fate of the Greek nobles however was that the fathers were slain, the boys taken to the barracks of the Janissaries and the women and girls to the harems of the sultan and his chief favorites. Some forty thousand Greeks perished during the siege, fifty thousand it is supposed became captives, ten thousand, it is possible, some few rich, most the very poor, retained their freedom if not their homes.”
By mid-day the devastation in the oldest central part of the city was so complete, with blood spilling downhill from high Petra and broken limbs scattered everywhere, that Mehmet contravened Islamic law and declared the pillage over after a single day rather than the traditional three. Many parts of the once-vast metropolis had grown so distant and distinct that the Turks did not realize that they belonged to the City, and accepted their opportune surrenders, sparing them the worst of the pillage. With who knows what exactly on his mind, the young Conqueror rode through the gore to St. Sophia and, having modestly anointed his turban with a handful of dust, entered the church, pausing to rebuke a Turkish soldier who was hacking with his sword at the marble pavement, before granting the lives of a few remaining priests, and ordering one of the ulema to proclaim the word of God from the high altar. With that performative utterance the great church, “naked and desolate,” denuded of worshippers and treasures, was transformed into a mosque. Later that day, he made a tour of the old Sacred Palace; a studious and thoughtful Conqueror, Mehmet was heard to murmur lines from a Persian poet: “The spider weaves the curtains in the palace of the Caesars; the owl calls the watches in Afrasiab’s towers.”
The French savant René Guerdan makes his mid-20th century account more suspenseful by supposing that the promised Venetian fleet was actually at anchor in Chios, awaiting a favorable wind, and was overlooked when a brigantine sent to search for it passed close by. “One windy day—on such things hang the fate of empires and the course of history.”
But other scholars—unromantic, English— maintain that the armada sailed too late to change history; it made haste slowly, in the Roman way, awaiting developments in the Venetian, and carried an ambassador authorized to deal with the sultan just in case. Mortally wounded, Giustiniani reached Chios, an island with which his family had been so closely identified for the last century that all the boys born there were given their surname; he died after a few days, having outlived both the Empire and his heroic reputation, at least among Greeks. May 29, 1453, was a Tuesday, a day that Greeks still consider to be one of ill omen, unsuited for beginning a trip or launching an enterprise.
As commander, Mehmet had reserved for himself the surviving flowers of Byzantine nobility. After Giustiniani’s desertion Constantine, realizing the cause was hopeless, discarded his imperial regalia, and threw himself into the fray at the St. Romanus Gate, never to be seen again; at least not altogether. According to one story, a headless body was discovered underneath a pile of corpses, distinguished by calf-length buskins stamped with the imperial eagle. The Turks routinely decapitated their fallen foes, and, considering the honors they expected, it is not surprising that a pair of Turkish soldiers soon enough presented Mehmet with a head that some of Constantine’s surviving—and presumably terrified— courtiers opportunely identified as his. By one or another account, the last emperor’s remains were given a decent Christian burial, or his head was stuffed and sent on a gruesome tour of the Middle East. As for Mehmet’s treatment of the living, Runciman tells,
He freed at once most of the noble ladies, giving many of them money so that they might redeem their families; but he retained the fairest of their young sons and daughters for his own seraglio. Many other youths were offered liberty and commissions in his army on condition that they renounce their religion. A few apostatized; but the greater part preferred to accept the penalties of loyalty to Christ.
The sultan was less lenient with the Italian and Catalan commanders who were trapped in the City: without ado they were executed.
Mehmet’s great catch was the grand duke himself, Lucas Notaras, who by now had ample opportunity to reconsider his quip about the cardinal’s hat vs. the sultan’s turban. Mehmet had treated the grand duke with elaborate courtesy, allowing him to return to his palace, and dangling the possibility of appointing him as the governor responsible for the Greek remnant in the City. That was until Mehmet, hearing that the grand duke’s sole surviving son, a fourteen-year-old, was a beauty, demanded him for his household. When the grand duke refused the eunuch who had been sent to fetch the boy, Mehmet ordered him, his son, and his luckless son-in-law who was paying a visit to be arrested and hustled to his presence. When Notaras remained unyielding, they were decapitated at the sultan’s banqueting table; in a last courtesy he granted the grand duke’s plea that the young men be killed before him, lest seeing him cut down shake their steadfastness. Almost immediately, Mehmet, leaving the desolate City for his capital at Edirne, disposed of what remained of the old power elite; “before his departure,” so Gibbon says, “the Hippodrome streamed with the blood of his noblest captives.” But were there so many left to slaughter? In a final dispersal, lots of four hundreds of nobly-born children and youths were shipped to the Muslim rulers of Granada, Tripoli, and Egypt.
“At the end of the year 1492,” as Samuel Eliot Morison paints the scene in his monumental life of Columbus, Admiral of the Ocean Sea (1942),
most men in Western Europe felt exceedingly gloomy about the future. Christian civilization appeared to be shrinking in area and dividing into hostile units as its sphere contracted. For over a century there had been no important advance in natural science, and registration in the universities dwindled as the instruction they offered became increasingly jejune and lifeless. Institutions were decaying, well-meaning people were growing cynical or desperate, and many intelligent men, for want of something better to do, were endeavoring to escape the present through studying the pagan past.
Islam was now expanding at the expense of Christendom.
Morison’s readers in 1942—which he called “a day of tribulation for Europe and for America”—could hardly mistake the implied parallel with the Axis conquests since 1939, which, extending from the gates of Stalingrad to Malaya, reached their fullest extent in that year.
Hugh Trevor-Roper picks up the story in an essay published in the 1950s, during one of the big freezes of the Cold War.
To us the great fact of the fifteenth and sixteenth centuries is the expansion of Europe by the spectacular discovery of new continents; to contemporaries it was its diminution by the spectacular advance of the Turkish Empire. In France, between 1480 and 1609, twice as many books were published upon the Turks as upon America, and the greatest of the observers of Turkey, the Belgian Busbecq, complained that the nations of Christendom were gathering useless empires at the end of the world while losing the heart of Europe…
Trevor-Roper’s “A Case of Co-Existence: Christendom and the Turks” had a polemical edge. If Europe in the 16th and 17th centuries had learned to live with the Turks, couldn’t liberal Western democracy peacefully, if watchfully, co-exist with the Soviet bloc?
The Conqueror’s great-grandfather Murad I had institutionalized two practices which would define the emergent empire: the creation of a slave-soldier caste by the conscription of Christian boys, who, circumcised and converted to Islam, became the sultan’s Janissary corps, the foundation of his military machine; and the sanctioned execution by a new sultan of his brothers, uncles, and any other male relations who threatened to contest their supremacy. (Mehmet had his baby brother Ahmed strangled in a bath.) As Marc David Baer dispassionately observes, “Such an arrangement was little different from the internecine warfare to obtain the thrones of Western Europe at the same time, such as the Wars of the Roses in England. The difference with the Ottomans was that the bloodshed was systematized and legalized.”
In the long reign of Suleiman the Magnificent the sultan’s writ was extended from the Euphrates to the Nile to the verge of the Danube. His conquests in the Middle East, Mecca and Medina, Jerusalem and Egypt, made him the world spokesman and protector of Islam, succeeding the Abbasids.
The difference seemed salient enough to the princes and prelates of the West, who might sometimes parlay with the Ottomans, but would never accept them as the legitimate heirs of Constantine (as the sultans insisted they were, by right of conquest). Within their ever vaster domain they exercised an absolute power over multitudes of subject races, not excluding the Turks themselves, a privileged but powerless caste: none of Western Europe’s absolute monarchs ever aspired even in theory to the absolutism that the sultans (or, in time, their viziers on their behalf ) exercised in fact. No wonder, as Trevor-Roper writes: “Throughout the sixteenth century Europeans were alternately fascinated and terrified by the Turks; by their silent, invincible, victorious armies, by their mixture of cruelty and toleration, their system of political slavery and their private moral virtues.”
In the long reign of Suleiman the Magnificent the sultan’s writ was extended from the Euphrates to the Nile to the verge of the Danube. His conquests in the Middle East, Mecca and Medina, Jerusalem and Egypt, made him the world spokesman and protector of Islam, succeeding the Abbasids. From the gates of Vienna, which he besieged, to the open Mediterranean, Suleiman’s great antagonist and Christian counterpart was the Habsburg emperor- king Charles V. The German popular historian Emil Ludwig draws a vivid sketch of their rivalry in The Mediterranean: Saga of a Sea (1942):
Both men were warriors—the Turk a conqueror, the Spanish rather a pretender to countries over which his dynasty had long quarreled with other dynasties. But Solyman needed war and would have died of boredom in his castle and harem. Charles could have lived without conquest…. If no one had rebelled against him he would merely have administered his inherited world empire. The Turk, on the contrary, wanted to win a world empire. Starting wars on the slightest pretext he took Rhodes, Bagdad [sic], and Belgrade, conquered Transylvania and Kurdistan. Charles, after deposing one Pope, picked another to perform his coronation, and this not even in Rome.
Yes, but Suleiman, as the first sultan to assume the title of caliph, effectively was pope and emperor, like the fisherman’s wife in the Brothers Grimm fairy tale. Charles thwarted Suleiman’s grand design to conquer Germany, just as Suleiman at a vast distance dealt Charles his worst defeat in the trenches of Tunis when he almost lost his life to the sultan’s pirate admiral, Barbarossa, thwarting his design to be lord of the ages, the greatest man of his time. “This,” says Emil Ludwig, “was something Charles had had every prospect of, because Cortez was then just conquering Mexico.”
Fernand Braudel, in his stupendous history, gives the back of his hand to the once fashionable thesis that it was the loss of the Levant to the Turks that turned the West westward, noting pointedly that “the Turkish occupation of Egypt in January, 1517 did not occur until twenty years after Vasco da Gama had sailed around the Cape of Good Hope.” Philip II inherited his father Charles’s dream of a “Universal Monarchy” under his Catholic majesty, but not the title of emperor, which passed to Charles’s brother Ferdinand upon his abdication. Philip’s conquest of the archipelago that became the Philippines and the peaceful annexation of Portugal and its overseas possessions combined in his person a world-straddling “Spanish dominion” on which the sun never set. It was the Ottoman sultans’ grand boast to be “Lords of the Horizon,” but it was the Habsburgs, with whom the Ottomans reluctantly conceded equality in a treaty of 1606, who commanded the farthest horizons.
The farthest flung of Spain’s claimed dominions in the New World was Alta California, at the northwest corner of the vast province of New Spain. Cortés, the conqueror of Tenochtitlan, led an expedition which “discovered” the Gulf of Mexico. The reconnoitering that followed led to nothing in the way of booty, plausible slaves, or settlement. For two centuries from the 1560s Spain’s Manila galleons sailed the long way, guided by the Japanese current, from Manila to Acapulco, Mexico, missing the Golden Gate (invisible in the summer fog).
Francis Drake, the English bravo despised as a privateer by the Spanish but lionized at home, anchored his 100-ton schooner, the Golden Hinde, for a month in June 1579, in Drake’s Bay, claiming the land as New Albion. Fanciful revisionists insist his landing was elsewhere, perhaps far to the north—but no one walking the Estero, wondering at the white cliffs so like Dover Beach, and admiring the bathers braving the surf, freezing even in summer, can doubt from the haunting atmosphere that this is where Drake and his crew spent their time—longer than would any Europeans in Alta California, for two centuries—and were waved good-bye when they departed by the bemused coastal Miwok, who were probably relieved to see them go.
Panorama of Drake’s Bay. Wikipedia Commons
In all of the part of North America now occupied by the United States—or so authority currently agrees—no place was more thickly settled than the California coast, or so peaceful. Certainly as compared to the feudal arrangements and tortuous ritualized warfare of the present northeast, as recently depicted in the Finnish scholar Pekka Hamalainen’s Indigenous Continent: The Epic Contest for North America (2020), and Bernard Bailyn’s Barbarous Years: The Peopling of British North America: The Conflict of Civilizations (2012).
“I am also always puzzled,” writes Czesław Miłosz, the Polish-American Nobel Prize-winning poet, who, for a long time while a professor at Berkeley, surveyed the scene from atop Grizzly Peak Boulevard—“I am also always puzzled why the white man steered clear of California for so long, though word of it had reached him through the accounts of sailors. But, after all, those were unfavorable reports: a foggy ocean, parched cliffs, impenetrable forests, thorny brushwood.”
In 1602 the tireless navigator Sebastián Vizcaíno sailed from Acapulco to wild Cape Mendocino. His journey retraced the epic voyaging of the conquistador Juan Rodríguez Cabrillo in 1542-43, who, proceeding north from La Navidad, managed to sail as far as Point Reyes before returning to the Santa Barbara Channel islands where he died. After Vizcaíno, so far as history records (the records were kept as state secrets by the English and the Spanish) there would be no European reconnoitering in California for 167 years. What was there to see, to do, to conquer, in this foggy, far-away, forlorn place, beyond the horizon? They let it be.
Sources:
I have not attempted to reconcile the different spellings of names in quoted sources. All unattributed quotations are from Gibbon’s Decline and Fall in the edition cited below.
Marc David Baer, The Ottomans: Khans, Caesars, and Caliphs. New York, 2021.
Fernand Braudel, The Mediterranean and the Mediterranean World in the Age of Philip II, vol. II, 1949, 2d revised edition 1966, English trans. by Sian Reynolds. New York, 1973.
Edward Gibbon, The Decline and Fall of the Roman Empire, vol. six, Everyman edition edited by Oliphant Smeaton, M.A. London, 1900.
René Guerdan, Byzantium: Its Triumphs and Tragedy, translated by D.L.B. Hartley, preface by Charles Diehl. 1957; rpt. New York, 1962.
Czesław Miłosz, Visions from San Francisco Bay, translated by Richard Lourie. New York, 1982.
Steven Runciman, The Fall of Constantinople, 1453. Cambridge, 1965.
H. R. Trevor-Roper, “A Case of Co-Existence: Christendom and the Turks,” in Men and Events: Historical Essays. New York, 1957.