From the flaming and flashing of certain igneous mixtures and the terror inspired by their noise, wonderful consequences ensue which no-one can guard against or endure … when a quantity of this powder, no bigger than a man’s finger, be wrapped up in a piece of parchment and ignited, it explodes with a blinding flash and a stunning noise. If a larger quantity were used, or the case were made of some more solid material, the explosion would be much more violent and the flash and noise altogether unbearable.
Roger Bacon, thirteenth-century English monk, on the effects of gunpowder
With the arrival of the Genoese contingent the preparations for a siege were carried forward with greater urgency. Giustiniani, who was “an expert in the art of wall fighting,” appraised the city’s defenses with a cool eye and took appropriate measures. Under his direction, during February and March they “dredged the fosse and repaired and built up the walls, restoring the battlements, refortifying inner and outer towers and strengthening the whole wall – both the landward and seaward sectors.”
Despite their dilapidated condition, the city still possessed formidable fortifications. Among all the many explanations for the longevity of Byzantium, the impregnable defenses of its capital city remain a cardinal factor. No city in the world owed as much to its site as Constantinople. Of the twelve miles of its perimeter, eight were ringed by sea. On the south side, the city was fringed by the Sea of Marmara, whose swift currents and unexpected storms made any sea-borne landing a risky undertaking. In a thousand years no aggressor ever seriously attempted an attack at this point. The seashore was guarded by a single unbroken wall at least fifty feet above the shoreline interspersed with a chain of 188 towers and a number of small defended harbors. The threat to this wall came not from ships but from the ceaseless action of the waves undermining its foundations. At times nature was more brutal still: in the bitter winter of 764 the sea walls were crushed by ice floes that rode up over the parapets. The whole length of the Marmara wall was studded with marble inscriptions commemorating the repairs of successive emperors. The sea ran strongly around this shoreline as far as the tip of the Acropolis point, before turning north into the calmer waters of the Golden Horn. The Horn itself provided an excellent sheltered anchorage for the imperial fleet; 110 towers commanded a single wall along this stretch with numerous water gates and two substantial harbors, but the defenses were always considered vulnerable. It was here that the Venetians had driven their ships up on the foreshore during the Fourth Crusade, overtopping the ramparts and storming the city. In order to block the mouth of the Horn in times of war, the defenders had been in the habit since the Arab siege of 717 of drawing a boom across the entrance of the Horn. This took the form of a 300-yard chain, consisting of massive cast-iron links each twenty inches long that were supported on sturdy wooden floats. With the goodwill of the Genoese, the chain could then be secured to a tower on the sea wall of Galata on the far side. During the winter months both chain and floats were prepared against the possibility of a naval attack.
Inscription on the walls: “The Tower of St. Nicholas was restored from the foundations, under Romanus, the Christ-loving Sovereign”
The base of the triangle of the city’s site on the westward side was protected by the four-mile land wall, the so-called wall of Theodosius, which ran across the grain of the land from the Sea of Marmara to the Golden Horn and sealed off Constantinople from any conventional land-borne assault. Many of the most significant events in the history of the city had been played out along this extraordinary structure. It almost matched the city itself in longevity, and projected a sense of legendary immutability within the Mediterranean world. For many approaching Constantinople across the flat Thracian plains as a trader or pilgrim, an ambassador from a Balkan court, or a plundering army with pretensions to conquest, the first sight of Constantinople at its apogee was the ominous prospect of the land walls riding the gentle undulations of the landscape from horizon to horizon in a regular unbroken succession of ramparts and towers. In the sunlight the limestone walls created a facade of brilliant white, banded with horizontal running seams of ruby-red Roman brick and arrow slits similarly arched; the towers – square, hexagonal, octagonal, occasionally circular – were so close together that, as one crusader put it, “a seven-year-old boy could toss an apple from one turret to the next.” They rose up in successive tiers to the summit of the inner wall, where the eagle banners of the emperor fluttered proudly in the wind. At intervals the eye could pick out the darkness of a heavily guarded entrance to the city through which men and animals vanished in times of peace, and at the western end, close to the Sea of Marmara, a gateway paneled with flat plates of gold and decorated with statues of marble and bronze shining in the sun. This was the Golden Gate, the great ceremonial archway flanked by two massive towers of polished marble through which, in the heyday of Byzantium, emperors returned in triumph with the visible tokens of their victories: conquered kings walking in chains, recaptured sacred relics, elephants, outlandishly dressed barbarian slaves, carts piled high with booty, and the whole might of the imperial army. By 1453 the gold and many of the decorations were gone, but the structure was still an impressive monument to Roman glory.
The walls in cross section showing the three defensive layers: inner and outer walls and moat
The man responsible for the land wall, built to define the mature limits of the city, was not the boy emperor Theodosius after whom it was named, but a leading statesman of the early fifth century, Anthemius, “one of the wisest men of the age,” for whose farsightedness the city owed a limitless debt of gratitude. The first line of the walls built in 413 deterred Attila the Hun, “the scourge of God,” from making an attack on the city in 447. When it collapsed under a severe earthquake the same year with Attila ravaging Thrace not far away, the whole population responded to the crisis. Sixteen thousand citizens totally rebuilt the wall in an astonishing two months, not just restoring Anthemius’s original structure, but adding an outer wall with a further string of interspaced towers, a protecting breastwork, and a brick-lined moat – the fosse – to create a formidable barrier of extraordinary complexity. The city was now protected on this side by a chain of 192 towers in a defensive system that comprised five separate zones, 200 feet wide and 100 feet high from the bed of the moat to the top of the tower. The achievement was recorded with a suitably boastful inscription: “in less than two months, Constantine triumphantly set up these strong walls. Scarcely could Pallas have built so quickly so strong a citadel.”
In its mature form, the Theodosian wall summarized all the accumulated wisdom of Greco-Roman military engineering about defending a city before the age of gunpowder. The heart of the system remained the inner wall constructed by Anthemius: a core of concrete faced on both sides by limestone blocks quarried nearby, with brick courses inserted to bind the structure more firmly. Its fighting ramparts were protected by battlements and reached by flights of steps. In line with Roman practice, the towers were not bound to the walls, ensuring that the two structures could each settle at their own rate without breaking apart. The towers themselves rose to a height of sixty feet and consisted of two chambers with a flat roof on which engines to hurl rocks and Greek fire could be placed. Here the sentinels scanned the horizon unceasingly, keeping themselves awake at night by calling out to one another down the line. The inner wall was forty feet high; the outer one was lower, about twenty-seven feet high, and had correspondingly lower towers that interspaced those on the inner wall. The two walls were separated by a terrace sixty feet wide, where the troops defending the outer wall massed, ready to engage the enemy at close quarters. Below the outer wall was another terrace sixty feet wide providing a clear killing field for any aggressor who made it over the moat. The brick-lined moat itself was another sixty-feet-wide obstacle, surmounted by a wall on the inner side; it remains unclear whether it was in parts flooded in 1453 or simply comprised a dry ditch. The depth and complexity of the system, the stoutness of its walls, and the height from which it commanded its field of fire rendered the Theodosian wall virtually impregnable to an army equipped with the conventional resources of siege warfare in the Middle Ages.
Along its length the land wall was pierced by a succession of gates. Some gave access to the surrounding countryside via bridges over the moat, which would be destroyed in the run-up to a siege; others, the military gates, allowed connection between the different layers of the walls and were used to move troops about within the system. The wall also contained a number of posterns – small subsidiary doorways – but the Byzantines were always aware of the danger these sally ports posed for the security of their city and managed them rigorously. In general the two sets of gates alternated along the length of the wall, with the military gates being referred to by number while the public gates were named. There was the Gate of the Spring, named after a holy spring outside the city, the Gate of the Wooden Circus, the Gate of the Military Boot Makers, the Gate of the Silver Lake. Some spawned multiple names as associations were forgotten and new ones created. The Third Military Gate was also referred to as the Gate of the Reds, after a circus faction in the early city, while the Gate of Charisius, a leader of the blue faction, was also called the Cemetery Gate. And into the structure were built some remarkable monuments that expressed the contradictions of Byzantium. Toward the Golden Horn the imperial palace of Blachernae nestled behind the wall, a building said once to be of such beauty that foreign visitors could find no words to describe it; adjoining it, the dank and dismal prison on Anemas, a dungeon of sinister reputation, scene of some of the most ghastly moments in Byzantine history. Here John V blinded both his son and his three-year-old grandson, and from here one of Byzantium’s most notorious emperors, Andronikos the Terrible, already horribly mutilated, was led out on a mangy camel among taunting crowds to the Hippodrome, where he was strung upside down between two columns and mockingly slaughtered.
The continuous life of the wall was so long that a deep accretion of history, myth, and half-forgotten associations attached to the various sectors. There was hardly a place that had not witnessed some dramatic moment in the city’s history – scenes of terrible treachery, miraculous deliverance, and death. Through the Golden Gate Heraclius brought the True Cross in 628; the Gate of the Spring saw the stoning of the unpopular emperor Nicephorus Phocas by an enraged mob in 967 and the restoration of the Orthodox emperors after Latin rule in 1261 when the gate was opened from within by sympathizers. The dying emperor Theodosius II was carried through the Fifth Military Gate in 450 following a fall from his horse in the valley outside, while the Gate of the Wooden Circus was blocked up in the twelfth century after a prophecy that the emperor Frederick Barbarossa would use it to capture the city.
Next to St. Sophia itself no structure expressed the psychic life of the city’s people as powerfully as the walls. If the church was their vision of heaven, the wall was their shield against the battering of hostile forces, under the personal protection of the Virgin herself. During sieges the constant prayer and the procession of her sacred relics along the ramparts were considered by the faithful to be generally more crucial than mere military preparations. A powerful spiritual force field surrounded such actions. Her robe, housed at the nearby church at Blachernae, was accorded more credit for seeing off the Avars in 626 and the Russians in 860 than military engineering. People saw visions of guardian angels on the ramparts, and emperors inserted marble crosses and prayers into the outward facing walls. Near the center point of the wall there was a simple talisman that expressed Constantinople’s deepest fear. It said: “O Christ God, preserve your city undisturbed and free from war. Conquer the fury of the enemies.”
At the same time, the practical maintenance of the walls was the one essential public work for the city, in which every citizen was required to help, without exemption. Whatever the state of the Byzantine economy, money was always found to patch up the wall. It was sufficiently important to have its own special officials under the overall authority of the impressively named “Count of the Walls.” As time and earthquakes shattered towers and crumbled masonry, running repairs were marked by a wealth of commemorative marble inscriptions set into the stonework. They spanned the centuries from the first reconstruction in 447 to a total renovation of the outer wall in 1433. One of the last dated repairs before the siege expressed the cooperation of divine and human agencies in the maintenance of the city’s shield. It read: “This God-protected gate of the life-giving spring was restored with the co-operation and at the expense of Manuel Bryennius Leontari, in the reign of the most pious sovereigns John and Maria Palaeologi in the month of May 1438.”
Perhaps no defensive structure summarized the truth of siege warfare in the ancient and medieval world as clearly as the walls of Constantinople. The city lived under siege for almost all its life; its defenses reflected the deepest character and history of the place, its mixture of confidence and fatalism, divine inspiration and practical skill, longevity and conservatism. Like the city itself, the walls were always there, and for anyone in the eastern Mediterranean, it was assumed they always would be. The structure of the defenses was mature in the fifth century and changed little thereafter; the building techniques were conservative, harking back to practices of the Greeks and Romans. They had no particular reason to evolve because siege warfare itself remained static. The basic techniques and equipment – blockade, mining, and escalade, the use of battering rams, catapults, towers, tunnels, and ladders – these were largely unchanging for longer than anyone could recall. The advantage always lay with the defender; in the case of Constantinople its coastal position increased that weighting. None of the armies camped before the land walls had ever succeeded in effecting an entry through the multiple defensive layers, while the city always took prudent measures as a matter of state policy to keep its cisterns brimming and its granaries full. The Avars came with an impressive array of stone-throwing machinery, but their looping trajectory made them far too puny to breach the walls. The Arabs froze to death in the cold. The Bulgar Khan Krum tried magic – he performed human sacrifices and sprinkled his troops with seawater. Even its enemies came to believe that Constantinople was under divine protection. Only the Byzantines themselves were ever successful in taking their own city from the land, and always by treachery: the messy final centuries of civil war produced a handful of instances where gates were flung open at night, usually with inside help.
There were just two places where the land wall could be considered potentially weak. In the central section the ground sloped down a long valley to the Lycus River and then up the other side. As the wall followed the downward slope, its towers no longer commanded the high ground and were effectively below the level occupied by a besieging army on the hill beyond. Furthermore the river itself, which was ducted into the city through a culvert, made it impossible to dig a deep moat at this point. Nearly all besieging armies had identified this area as vulnerable, and though none had succeeded, it provided attackers with a vestige of hope. A second anomaly in the defenses existed at the northern end. The regular procession of the triple wall was suddenly interrupted as it approached the Golden Horn. The line took an abrupt right-angle turn outward to include an extra bulge of land; for 400 yards, until it reached the water, the wall became a patchwork structure of different-shaped bastions and sectors, which, though stoutly built on a rocky outcrop, was largely only one line deep and for much of its length unmoated. This was a later addition undertaken to include the sacred shrine of the Virgin at Blachernae. Originally the church had been outside the walls. With a typical Byzantine logic it had been held initially that the protection of the Virgin was sufficient to safeguard the church. After the Avars nearly burned it in 626 – the shrine was saved by the Virgin herself – the line of the wall was altered to include the church, and the palace of Blachernae was also built in this small bight of land. Both these perceived weak spots had been keenly appraised by Mehmet when he reconnoitered in the summer of 1452. The right-angle turn where the two walls joined was to receive particular attention.
As they patched up their walls under Giustiniani’s direction and paraded the sacred icons on the ramparts, the people of the city could be pardoned for expressing confidence in their protective powers. Immutable, forbidding, and indestructible, they had proved time and again that a small force could keep a huge army at bay until its willpower collapsed under the logistical burden of siege, or dysentery, or the disaffection of the men. If the walls were decayed in places, they were still basically sound. Brocquière found even the vulnerable right angle to be protected by “a good and high wall” when he came in the 1430s. The defenders, however, were unaware that they were preparing for conflict on the cusp of a technological revolution that would profoundly change the rules of siege warfare.
No one knows exactly when the Ottomans acquired guns. Gunpowder weapons probably made their way into the empire through the Balkans sometime around 1400. By medieval standards this was a technology traveling at lightning speed – the first written mention of a gun does not occur until 1313, the first pictorial representation dates from 1326 – but by the end of the fourteenth century, cannon were being widely manufactured across Europe. Small-scale workshops for the production of iron and bronze guns mushroomed in France, Germany, and Italy, and secondary industries developed around them. Saltpeter “factories” sprang up; middlemen imported copper and tin; technical mercenaries sold their skills in metal casting to the highest bidder. In practical terms the benefits of early gunpowder weapons were dubious: field artillery present at the battle of Agincourt beside the longbow made little material difference. The weapons themselves were cumbersome, tedious to prepare, impossible to aim with any accuracy, and as dangerous to their crews as to the enemy. However, cannon fire undoubtedly had a psychological effect. King Edward III at Creçy “struck terror into the French Army with five or six pieces of cannon, it being the first time they had seen such thundering machines” and the giant Dutch gun of Philip van Artevelde in 1382 “made such a noise in the going as though all the devils of hell had been in the way.” Metaphors of the inferno are common to these early accounts. There was something infernal about the thunderous roar of “the devilish instrument of war”: it upturned the natural order of things and stripped the chivalry out of combat. The church placed a ban on the use of fiery compositions for military purposes as early as 1137 and anathematized the crossbow for good measure, but it made little difference. The genie had exploded out of the bottle.
With the exception of sieges, the contribution of artillery to the conduct of warfare was still minimal by 1420, the moment when the Ottomans started to show a serious interest. Pushing into the Balkans, they captured the resources and the craftsmen to begin manufacturing guns of their own. These included foundries and skilled foundry men, copper mines, cutters of stone balls, makers of saltpeter, and gunpowder factories. The Ottomans learned fast. They were hugely receptive to new techniques and adept at integrating skilled Christians into their armies and training their own soldiers too. Murat, Mehmet’s father, created the infrastructure for an artillery force, forming a gunnery corps and corps of gun-carriage drivers in the palace army. At the same time, despite a papal edict that outlawed gunrunning to the infidel, Venetian and Genoese merchants shipped weapons across the eastern Mediterranean, and technical mercenaries, keen to sell their skills to the rising sultanate, made their way to the Ottoman court.
Constantinople experienced its first taste of this new capability in the summer of 1422 when Murat laid siege to the city. The Greeks record that he brought huge “bombards” to the walls under the direction of Germans – and that they were largely ineffective: seventy balls struck one tower without inflicting significant damage. When Murat brought guns to another wall twenty-four years later, the story was completely different. In the 1440s Constantine was attempting to protect one of the city’s few remaining provinces, the Peloponnese, from Ottoman incursions and rebuilt a six-mile wall, the Hexamilion, across the Isthmus of Corinth from sea to sea to fence it off. It was a substantial piece of military engineering thought capable of withstanding prolonged assault. Early in December 1446 Murat attacked the wall with long cannon and breached it in five days. Constantine barely escaped with his life.
Packing a cannon with gunpowder
In between the two events the Ottomans had deepened their knowledge of artillery, and they had done so at a critical moment in the evolution of cannon construction and explosives. Sometime in the 1420s a development took place throughout Europe in the manufacture of gunpowder that substantially increased its potency and stability. Up till then it had been the practice to carry the constituent ingredients – sulfur, saltpeter, and charcoal – in different barrels and to mix them on site. The resulting powder was slow burning, susceptible to damp, and had a tendency to separate out. In the early fifteenth century, experimentation revealed that mixing the ingredients into a paste and drying it into preformed cakes that could be broken down into granules as required produced better results. The so-called corned powder was faster burning, 30 percent more powerful, and more resistant to atmospheric moisture. A heavy shot could now be projected at a city wall with impressive momentum. By then giant siege guns, up to sixteen feet long and capable of hurling balls well over 750 pounds, had also begun to appear. Dulle Griete, the Great Bombard of Ghent, roared with a noise “made by the furies of Hell” and shattered the walls of Bourges in 1412. At the same time the new powder increased the danger to gunners and affected cannon founding: barrels were built stronger and longer, and there was a move to guns made in one piece, which had to be cast of bronze – and at a huge price differential. A bronze cannon cost three times as much as a forged iron one, but the exponential benefits evidently justified the expense. For the first time since trumpets flattened the walls of Jericho, a significant advantage was handed back to the side besieging a stoutly fortified castle. Fifteenth-century Europe rang to the roar of great siege guns, the shattering of stone balls against stone walls, and the sudden collapse of hitherto impregnable bastions.
The Ottomans were uniquely placed to take advantage of these developments. The expanding empire was self-sufficient in copper and naturally occurring saltpeter; it acquired the expertise by conquest or purchase and then set up the structures to disseminate it among its own army corps. It quickly became proficient in manufacturing, transporting, and firing its artillery – and was second to none in the deep logistical requirements of gunpowder warfare. To put an effective cannon battery in the field at a given moment made exceptional demands on medieval supply chains: adequate quantities of stone balls matched in caliber to the barrels and serviceable gunpowder had to coincide with the arrival of the slow-moving guns. The Ottomans sourced men and materials from across the empire – cannonballs from the Black Sea, saltpeter from Belgrade, sulfur from Van, copper from Kastamonu, tin from overseas trade, scrap bronze from the church bells of the Balkans – and distributed them through an overland transport network by cart and camel that was unmatched in its efficiency. Deep planning was a hallmark of the Ottoman military machine, and it transferred these talents naturally to the special requirements of the gunpowder age.
So rapid was the Ottoman assimilation of cannon technology that by the 1440s they had evidently acquired the unique ability, widely commented on by eyewitnesses, to cast medium-size barrels on the battlefield in makeshift foundries. Murat transported gunmetal to the Hexamilion and cast many of his long guns on the spot. This allowed extraordinary flexibility during siege warfare: rather than hauling the finished weapon to the siege, it could be transported more quickly in bits and could be broken up again afterward if need be. Guns that ruptured in use, as they frequently did, could be repaired and pressed back into service, and in an age when the match between gun caliber and available cannonballs could be uncertain, barrels could be tailor-made to the ammunition available. (This facility reached its logical conclusion during the epic siege of the Venetian city of Candia on Crete in the seventeenth century. After twenty-one years of fighting, the Ottomans had collected 30,000 Venetian cannonballs unusable in their own guns. They cast three new barrels matched to the enemy calibers and fired them back.)
For the Ottomans, the siege gun seemed to answer something particularly deep in the tribal soul: it fed their rooted opposition to defended settlements. The descendants of the steppe nomads had proved their continuous superiority in open battle; it was only when confronted with the city walls of sedentary peoples that military matters became intractable. Artillery offered the possibility of a quick solution to the dangers of long-drawn-out sieges. It immediately attracted Mehmet’s scientific interest as he considered the impregnable walls of the city. Early in his reign he began to experiment with casting large guns.
The Byzantines were also aware of the potential of gunpowder weapons. Within the city they had some medium-size cannon and handguns, for which Constantine made strenuous attempts to stockpile resources. He was successful in obtaining supplies of gunpowder from the Venetians, but the empire was too poor to invest heavily in expensive new weapons. Sometime, probably earlier than 1452, there arrived in the city a Hungarian cannon founder called Orban, seeking his fortune at the imperial court. He was one of the growing band of technical mercenaries who plied their trade across the Balkans; he offered the Byzantines his skill in casting large, single-piece bronze guns. The cash-strapped emperor was interested in the man but had few resources to use his skill; he authorized a tiny stipend to detain Orban in the city, but even this was not paid regularly. The luckless master craftsman became increasingly destitute; sometime during 1452 he left the city and made his way to Edirne to seek an audience with Mehmet. The sultan welcomed the Hungarian, provided him with food and clothes, and questioned him closely. The ensuing interview was vividly re-created by the Greek chronicler Doukas. Mehmet asked if he could cast a cannon suitable to project a stone large enough to smash the city walls, and gestured the size of the stone he had in mind. Orban’s reply was emphatic: “If you want, I can cast a cannon of bronze with the capacity of the stone you want. I have examined the walls of the city in great detail. I can shatter to dust not only these walls with the stones from my gun but the very walls of Babylon itself. The work required to make the gun, I can fully carry out, but,” he added, keen to limit his guarantee, “I don’t know how to fire it and I cannot guarantee to do so.” Mehmet ordered him to cast the cannon, and declared that he would see to its firing afterward.
Whatever the details of the actual interview, it seems that Orban set to work to create his first great gun sometime during the building of the Throat Cutter in the summer of 1452. At about this time, Mehmet must have started to stockpile substantial quantities of materials for guns and gunpowder: copper and tin, saltpeter, sulfur, and charcoal. He also seems to have sent out the order for masons to produce granite balls in quarries on the Black Sea. Within three months Orban had cast his first great gun, which was lugged to the Throat Cutter to guard the Bosphorus. It was this weapon that shattered Rizzo’s galley in November 1452 and first sent news of Ottoman artillery power rippling through the city. Satisfied with the results, Mehmet now ordered Orban to produce a truly monstrous cannon, double its size – the archetype of a supergun.
The Ottomans were probably already casting guns at Edirne by this time; what Orban brought was the skill to construct the molds and control the critical variables on a far greater scale. During the winter of 1452, he set to the task of casting what was probably the largest cannon ever built. This painstaking and extraordinary process was described in detail by the Greek chronicler Kritovoulos. Initially, a barrel-shaped mold some twenty-seven feet long was constructed of clay mixed with finely chopped linen and hemp. The mold was of two widths: the front compartment for the stone ball had a diameter of thirty inches, with a smaller after-chamber to take the powder. An enormous casting pit had to be excavated, and the fired clay core was placed in it with the muzzle facedown. An outer cylindrical clay casing “like a scabbard” was fashioned to fit over this and held in position, leaving space between the two clay molds to receive the molten metal. The whole thing was packed about tightly with “iron and timbers, earth and stones, built up from outside” to support the huge weight of the bronze. At the last moment wet sand would be drizzled around the mold and the whole thing covered over again, leaving just a hole through which the molten metal could be poured. Meanwhile Orban constructed two brick-lined furnaces faced with fired clay inside and out and reinforced with large stones – sufficient to withstand a temperature of 1,000 degrees centigrade – and surrounded on the outside by a mountain of charcoal “so deep that it hid the furnaces, apart from their mouths.”
The operation of a medieval foundry was fraught with danger. A visit by the later Ottoman traveler Evliya Chelebi to a gun factory catches the note of fear and risk surrounding the process:
On the day when cannon are to be cast, the masters, foremen and founders, together with the Grand Master of the Artillery, the Chief Overseer, Imam, Muezzin and timekeeper, all assemble and to the cries of “Allah! Allah!,” the wood is thrown into the furnaces. After these have been heated for twenty-four hours, the founders and stokers strip naked, wearing nothing but their slippers, an odd kind of cap which leaves nothing but their eyes visible, and thick sleeves to protect the arms; for, after the fire has been alight in the furnaces twenty-four hours, no person can approach on account of the heat, save he be attired in the above manner. Whoever wishes to see a good picture of the fires of Hell should witness this sight.
When the furnace was judged to have reached the correct temperature, the foundry workers started to throw copper into the crucible along with scrap bronze probably salvaged, by a bitter irony for Christians, from church bells. The work was incredibly dangerous – the difficulty of hurling the metal piece by piece into the bubbling cauldron and of skimming dross off the surface with metal ladles, the noxious fumes given off by the tin alloys, the risk that if the scrap metal were wet, the water would vaporize, rupturing the furnace and wiping out all close by – these hazards hedged the operation about with superstitious dread. According to Evliya, when the time came to throw in the tin:
the Vezirs, the Mufti and Sheiks are summoned; only forty persons, besides the personnel of the foundry, are admitted all told. The rest of the attendants are shut out, because the metal, when in fusion, will not suffer to be looked at by evil eyes. The masters then desire the Vezirs and sheiks who are seated on sofas at a great distance to repeat unceasingly the words “There is no power and strength save in Allah!” Thereupon the master-workmen with wooden shovels throw several hundredweight of tin into the sea of molten brass, and the head-founder says to the Grand Vizier, Vezirs and Sheiks: “Throw some gold and silver coins into the brazen sea as alms, in the name of the True Faith!” Poles as long as the yard of ships are used for mixing the gold and silver with the metal and are replaced as fast as consumed.
For three days and nights the lit charcoal was superheated by the action of bellows continuously operated by teams of foundry workers until the keen eye of the master founder judged the metal to be the right tone of molten red. It was another critical moment, the culmination of weeks of work, involving fine judgment: “The time limit having expired … the head-founder and master-workmen, attired in their clumsy felt dresses, open the mouth of the furnace with iron hooks exclaiming ‘Allah! Allah!’ The metal, as it begins to flow, casts a glare on the men’s faces at a hundred paces’ distance.” The molten metal flowed down the clay channel like a slow river of red-hot lava and into the mouth of the gun mold. Sweating workers prodded the viscous mass with immensely long wooden poles to tease out air bubbles that might otherwise rupture the gunmetal under fire. “The bronze flowed out through the channel into the mould until it was completely full and the mould totally covered, and it overflowed it by a cubit above. And in this way the cannon was finished.” The wet sand packed around the mold would hopefully slow the rate of cooling and prevent the bronze from cracking in the process. Once the metal was cold, the barrel was laboriously excavated from the ground like an immense grub in its cocoon of clay and hauled out by teams of oxen. It was a powerful alchemy.
Fifteenth-century cast cannon
What finally emerged from Orban’s foundry after the molds had been knocked out and the metal scraped and polished was “a horrifying and extraordinary monster.” The primitive tube shone dully in the winter light. It was twenty-seven feet long. The barrel itself, walled with eight inches of solid bronze to take the force of the blast, had a diameter of thirty inches, big enough for a man to enter on his hands and knees and designed to accommodate a monstrous stone shot eight feet in circumference weighing something over half a ton. In January 1453 Mehmet ordered a test firing of the great gun outside his new royal palace at Edirne. The mighty bombard was hauled into position near the gate and the city was warned that the following day “the explosion and roar would be like thunder, lest anyone should be struck dumb by the unexpected shock or pregnant women might miscarry.” In the morning the cannon was primed with powder. A team of workmen lugged a giant stone ball into the mouth of the barrel and rolled it back down to sit snugly in front of the gunpowder chamber. A lighted taper was put to the touch hole. With a shattering roar and a cloud of smoke that hazed the sky, the mighty bullet was propelled across the open countryside for a mile before burying itself six feet down in the soft earth. The explosion could be heard ten miles off: “so powerful is this gunpowder,” recorded Doukas, who probably witnessed this test firing personally. Mehmet himself ensured that ominous reports of the gun filtered back to Constantinople: it was to be a psychological weapon as well as a practical one. Back in Edirne, Orban’s foundry continued to turn out more guns of different sizes; none were quite as large as the first super-gun, but a number measured more than fourteen feet.
During early February, consideration turned to the great practical difficulties of transporting Orban’s gun the 140 miles from Edirne to Constantinople. A large detachment of men and animals was detailed for the task. Laboriously the immense tube was loaded onto a number of wagons chained together and yoked to a team of sixty oxen. Two hundred men were deployed to support the barrel as it creaked and lurched over the rolling Thracian countryside while another team of carpenters and laborers worked ahead, leveling the track and building wooden bridges over rivers and gullies. The great gun rumbled toward the city walls at a speed of two and a half miles a day.