On Thursday 31 August 1452 Mehmet’s new fortress was complete, a bare four and half months after the first stone was laid. It was huge, ‘not like a fortress’, in the words of Kritovoulos, ‘more like a small town’ and it dominated the sea. The Ottomans called it Bogaz Kesen, the Cutter of the Straits or the Throat Cutter, though in time it would become known as the European castle, Rumeli Hisari. The triangular structure with its four large and thirteen small towers, its curtain walls twenty-two feet thick and fifty feet tall and its towers roofed with lead, represented an astonishing building feat for the time. Mehmet’s ability to co-ordinate and complete extraordinary projects at breakneck speed was continually to dumbfound his opponents in the months ahead.
Throughout the West news of Murat’s death was greeted with relief. In Venice, Rome, Genoa and Paris they were all too ready to accept the opinion set out in a letter from the Italian Francesco Filelfo to King Charles of France a month later, that the young Mehmet was young, inexperienced and simple minded. They would probably have been less interested in his conclusion – that the time was ripe for a decisive military operation to drive the Ottomans, ‘a mob of venal corrupt slaves’, out of Europe for good. Any immediate appetite for crusading had been firmly scotched by the bloody debacle at Varna in 1444 and the potentates of Europe welcomed the prospect of the callow, and so far disastrous, Mehmet ascending the throne.
Those with a deeper knowledge of the Great Turk knew better. George Sphrantzes, Constantine’s most trusted ambassador, was crossing the Black Sea on his way from the King of Georgia to the Emperor of Trebizond at the time of Murat’s death. He was engaged in an interminable round of diplomacy, seeking a suitable match for the widowed Constantine with the aim of shoring up his beleaguered position, providing the possibility of an heir and filling his coffers with dowry. At Trebizond the Emperor John Komnenos greeted him jovially with word of Mehmet’s accession: ‘Come, Mr Ambassador, I have good news for you and you must congratulate me.’ Sphrantzes’ reaction was startling: ‘Overcome by grief, as if I had been told of the death of those dearest to me, I stood speechless. Finally, with considerable loss of spirit, I said: “Lord this news brings no joy; on the contrary, it is a cause for grief.”’ Sphrantzes went on to explain what he knew of Mehmet – that he was ‘an enemy of the Christians since childhood’ and keen to march against Constantinople. Moreover Constantine was so short of funds that he needed a period of peace and stability to repair the city’s finances.
Back in Constantinople ambassadors were hastily dispatched to Edirne to present their respects to the young sultan and seek reassurance. They were pleasantly surprised by the reception. Mehmet exuded sweet reasonableness. He is said to have sworn by the Prophet, the Koran, ‘and by the angels and archangels that he would devote himself to peace with the City and the Emperor Constantine for his whole life’. He even granted the Byzantines an annual sum from the tax revenues of some Greek towns in the lower Struma valley that legally belonged to Prince Orhan, the Ottoman pretender. The money was to go towards the upkeep of Orhan so long as he was detained in the city.
The stream of embassies that followed was similarly reassured. In September the Venetians, who had trading interests in Edirne, renewed their peace with Mehmet, while the Serbian despot, George Brankovič, was soothed by the return of his daughter Mara, who had been married to Murat, and the handing back of some towns. Mehmet, for his part, requested George’s help in brokering a deal with the Hungarians, whose brilliant leader, the regent John Hunyadi, presented the most potent threat from Christian Europe. As Hunyadi needed to crush some domestic intrigues of his own, he was willing to agree a three-year truce. Emissaries from the Genoese at Galata, from the Lords of Chios, Lesbos and Rhodes, from Trebizond, Wallachia and Ragusa (Dubrovnik) were similarly able to secure guarantees of peace on reasonable terms. By the autumn of 1451 it was commonly accepted in the West that Mehmet was firmly under the thumb of his peaceable vizier, Halil Pasha, and would pose a threat to no one – and it seems too that many at Constantinople, less wary or less experienced than Sphrantzes, were similarly lulled. It suited kings and potentates across the Christian world to believe that all was well. Mehmet guarded his hand carefully.
Christians were not alone in misreading Mehmet’s strength of character. In the autumn of 1451, the troublesome Bey of Karaman tried yet again to wrest back territory in western Anatolia from Ottoman control. He occupied fortresses, reinstated former chieftains and invaded Ottoman land. Mehmet sent his generals to put down the uprising and having concluded his peace treaties at Edirne, appeared on the scene himself. The effect was immediate. The revolt was quickly crushed and Mehmet turned for home. At Bursa he encountered a further test of strength – this time from his own Janissary corps. ‘Standing with their arms in two rows on either side of the road, they shouted at him: “This was our sultan’s first campaign, and he should reward us with the customary bonus.”’ On the spot he was forced to accede; ten sacks of coins were distributed among the mutineers, but for Mehmet it was a crucial test of wills that he was determined to win. A few days later he summoned their general, castigated and stripped him of his office; several of the officer corps were similarly punished. This was the second revolt Mehmet had experienced and he recognized the imperative to secure the full loyalty of the Janissary corps if the capture of Constantinople were to be successful. Accordingly the regiment was restructured; he added 7,000 men from his personal household troops and gave command to a new general.
It was at this moment that Constantine and his advisers advanced an initiative of their own that demonstrated how little they understood Mehmet. Prince Orhan, the only other claimant to the Ottoman throne, was lodged in Constantinople, his upkeep paid for out of the tax revenues agreed with the sultan in the summer. The Byzantines dispatched ambassadors to Halil at Bursa with a peremptory demand:
the Emperor of the Romans does not accept the annual allowance of three hundred thousand aspers. For Orhan, who is equal to your leader as a descendant of Osman, has now come of age. Every day many flock to him. They call him lord and leader. He himself does not have the means to be generous to his followers, so he asks the Emperor, who because he lacks funds, cannot satisfy these requests. Therefore we ask one of two things: either double the allowance, or we will release Orhan.
The implication was clear enough – if the young sultan failed to pay, a rival claimant to the throne would be at large to foment civil war in the empire.
It was a classic ploy. Throughout its history, the exploitation of dynastic rivalry amongst adjacent states had been a cornerstone of Byzantine diplomacy. It had frequently offset periods of military weakness and earned Byzantium an unenviable and unequalled reputation for cunning. The Ottomans had had a prior taste of these tactics under Constantine’s father, Manuel II, when the dynasty had almost collapsed in a civil war shrewdly promulgated by the emperor, an episode of which Mehmet was keenly aware. Constantine evidently saw Orhan as a golden card, perhaps the only card left, and decided to play it. Under the circumstances it was a serious blunder – and almost inexplicable, given the knowledge of seasoned diplomats such as Sphrantzes about the politics of the Ottoman court. It may simply have been dictated by the state of the imperial finances rather than any realistic expectation of stirring up insurrection but it confirmed for the war party at the Ottoman court all the reasons why Constantinople must be taken. It was a proposal almost calculated to destroy Halil’s attempts at peacekeeping – and to endanger the vizier’s own position. The old vizier exploded with anger:
You stupid Greeks, I have had enough of your devious ways. The late sultan was a lenient and conscientious friend to you. The present sultan is not of the same mind. If Constantine eludes his bold and imperious grasp, it will be only because God continues to overlook your cunning and wicked schemes. You are fools to think that you can frighten us with your fantasies, and that when the ink on our recent treaty is barely dry. We are not children without strength or reason. If you think you can start something, do so. If you want to proclaim Orhan as sultan in Thrace, go ahead. If you want to bring the Hungarians across the Danube, let them come. If you want to recover the places which you lost long since, try this. But know this: you will make no headway in any of these things. All that you will achieve is to lose what little you still have.
Mehmet himself received the news with a poker face. He dismissed the ambassadors with ‘affable sentiments’ and promised to look into the matter when he returned to Edirne. Constantine had handed him an invaluable pretext for breaking his own word when the time was right.
On his way back to Edirne Mehmet discovered that it was impossible to cross to Gallipoli as he intended. The Dardanelles were blocked by Italian ships. Accordingly he made his way up the straits of the Bosphorus to the Ottoman fortress of Anadolu Hisari – ‘the Anatolian castle’ – built by his great grandfather Bayezit in 1395 at the time of his siege of the city. At this spot the distance that separates Asia from Europe shrinks to a mere 700 yards, and it affords the best point to cross the fast-flowing and treacherous waters, a fact known to the Persian king, Darius, who moved an army of 700,000 men across on a bridge of boats on his way to battle 2,000 years earlier. As Mehmet’s small fleet of ships scuttled back and forth ferrying men across to Europe his fertile mind pondered the Bosphorus and he seems to have come to a number of conclusions. The straits represented an area of vulnerability for the Ottomans: it was impossible to be the secure lord of two continents if crossing between them could not be guaranteed; at the same time, if he could find a way to dominate the Bosphorus, Mehmet could strangle the supply of grain and help to the city from the Greek colonies on the Black Sea and cut off the customs revenues it derived from shipping. The idea came to him to construct a second fortress on the European side, on land belonging to the Byzantines, to secure control of the straits, so that the ‘path of the vessels of the infidels may be blocked’. It was probably now that he also recognized the acute need for a larger fleet to counter Christian maritime superiority.
Once back at Edirne he took immediate action over the Byzantine ultimatum, confiscating the taxes from the towns on the Struma intended for Orhan’s maintenance and expelling its Greek inhabitants. Perhaps Constantine could already feel pressure tightening on the city; he had dispatched an envoy to Italy in the summer of 1451 who went first to Venice to seek permission to recruit archers from the Venetian colony of Crete and then to Rome with a message to the Pope. More likely, Constantine was still hopeful that positive offensive action could be taken against the new sultan: there was no hint of emergency in the messages sent to the Italian states.
As the winter of 1451 approached Mehmet was in Edirne, restlessly making plans. Here he surrounded himself with a group of Westerners, particularly Italians, with whom he discussed the great heroes of classical antiquity, Alexander and Caesar, his role models for the future that he intended. Remembering the disturbance among the Janissaries at Bursa in the autumn, he carried out further reforms of the army and the administration. New governors were appointed to some provinces, the pay of the palace regiments increased and he began to stockpile armaments and supplies. It is likely that he also embarked on a shipbuilding programme. At the same time the idea of the castle was taking shape in his mind. He sent out proclamations to every province of the empire requisitioning the services of thousands of masons, labourers and limekiln workers the following spring. Arrangements were also made for the collection and transportation of building materials – ‘stone and timber and iron and everything else that was useful’ … ‘for the construction of a castle at the Sacred Mouth above the city’ – near the site of the ruined church of St Michael.
The news of this decree swiftly reached Constantinople and the Greek colonies on the Black Sea and the islands of the Aegean. A mood of pessimism swept the people; old prophecies were recalled foretelling the end of the world: ‘now you can see the portents of the imminent destruction of our nation. The days of the Antichrist have come. What will happen to us? What should we do?’ Urgent prayers were offered up for deliverance in the city churches. At the end of 1451 Constantine dispatched another messenger to Venice with more urgent news: the sultan was preparing a massive build-up against the city and that unless help was sent it would surely fall. The Venetian Senate deliberated at its own speed and delivered their reply on 14 February 1452. It was characteristically cautious; they had no desire to compromise their commercial advantages within the Ottoman Empire. They suggested that the Byzantines should seek the co-operation of other states rather than relying on the Venetians alone, though they did authorize the dispatch of gunpowder and breastplates that Constantine had requested. Constantine meanwhile had no option but to make direct representations to Mehmet. His ambassadors trundled back over the hills of Thrace for another audience. They pointed out that Mehmet was breaking a treaty by threatening to build this new castle without consultation, that when his great grandfather had built the castle at Anadolu Hisari he had made this request of the emperor, ‘as a son would beg his father’. Mehmet’s response was short and to the point: ‘What the city contains is its own; beyond the fosse it has no dominion, owns nothing. If I want to build a fortress at the sacred mouth, it can’t forbid me.’ He reminded the Greeks of the many Christian attempts to bar Ottoman passage over the straits and concluded in typically forthright style: ‘Go away and tell your emperor this: “The sultan who now rules is not like his predecessors. What they couldn’t achieve, he can do easily and at once; the things they did not wish to do, he certainly does. The next man to come here on a mission like this will be flayed alive.”’ It could hardly be clearer.
In mid-March Mehmet set out from Edirne to start the building work. He went first to Gallipoli; from there he dispatched six galleys with some smaller warships, ‘well-prepared for a sea battle – in case that should be necessary’, and sixteen transport barges to carry equipment. He then made his way to the chosen spot by land with the army. The whole operation was typical of his style. Mehmet’s genius at logistical arrangements ensured that men and materials were mobilized on cue and in enormous quantities with the aim of completing the task in the shortest possible time. The governors of provinces in both Europe and Asia gathered their conscripted men and set out for the site. The vast army of workers – ‘masons, carpenters, smiths, and lime burners, and also various other workmen needed for that, without any lack, with axes, shovels, hoes, picks, and with other iron tools’ – arrived to start the work. Building materials were ferried across the straits in lumbering transport barges: lime and slaking ovens, stone from Anatolia, timber from the forests of the Black Sea and from Izmit, while his war galleys cruised the outer straits. Mehmet personally surveyed the site on horseback and in conjunction with his architects, who were both Christian converts, planned the details of the layout: ‘the distance between the outer towers and the main turrets and the gates and everything else he worked out carefully in his head’. He had probably sketched outline plans for the castle over the winter in Edirne. He oversaw the staking out of the ground plan and laid the cornerstone. Rams were killed and their blood mixed with the chalk and mortar of the first layer of bricks for good luck. Mehmet was deeply superstitious and strongly influenced by astrology; there were those who claimed the curious shape of the castle to be cabbalistic; that it represented the interwoven Arabic initials of the Prophet – and of Mehmet himself. More likely the layout was dictated by the steep and difficult terrain of the Bosphorus shore, comprising ‘twisting curves, densely wooded promontories, retreating bays and bends’ and rising to a height of two hundred feet from the shore to the apex of the site.
The work started on Saturday 15 April and was carefully organized under a system of competitive piecework that relied on Mehmet’s characteristic mixture of threats and rewards and involved the whole workforce, from the greatest vizier to the humblest hod carrier. The structure was four sided, with three great towers at its cardinal points linked by massive walls and a smaller fourth tower inserted into the south-west corner. The responsibility for building – and funding – the outer towers was given to four of his viziers, Halil, Zaganos, Shihabettin and Saruja. They were encouraged to compete in the speedy construction of their portion, which given the tense internal power struggles at court and the watchful eye of their imperious sultan who ‘gave up all thoughts of relaxation’ to oversee their work, was a powerful spur to performance. Mehmet himself undertook the building of the connecting walls and minor towers. The workforce of over 6,000, which comprised 2,000 masons and 4,000 masons’ assistants as well as a full complement of other workmen, was carefully subdivided on military principles. Each mason was assigned two helpers, one to work each side of him, and was held responsible for the construction of a fixed quantity of wall per day. Discipline was overseen by a force of kadis (judges), gathered from across the empire, who had the power of capital punishment; enforcement and military protection was provided by a substantial army detachment. At the same time Mehmet ‘publicly offered the very best rewards to those who could do the work quickly and well’. In this intense climate of competition and fear, according to Doukas even the nobility sometimes found it useful to encourage their workforce by personally carrying stones and lime for the perspiring masons. The scene resembled a cross between a small makeshift town and a large building site. Thousands of tents sprang up nearby at the ruined Greek village of Asomaton; boats manoeuvred their way back and forth across the choppy running currents of the strait; smoke billowed from the smouldering lime pits; hammers chinked in the warm air; voices called. The work went on round the clock, torches burning late into the night. The walls, encased in a lattice work of wooden scaffolding, rose at an astounding speed. Round the site spring unfolded along the Bosphorus: on the densely wooded slopes wisteria and judas trees put out their blossom; chestnut candles flowered like white stars; in the tranquil darkness, when moonlight rippled and ran across the glittering straits, nightingales sang in the pines.