There is a need for machines for conducting a siege: different types and forms of tortoises … portable wooden towers … different forms of ladders … different tools for digging through different types of walls … machines for mounting walls without ladders.
Tenth-century manual on siege craft
“Alas, most blessed Father, what a terrible disaster, that Neptune’s fury should drown them in one blow!” Recriminations for the failure of the night attack were bitter and immediate. The Venetians had lost eighty or ninety of their close companions in the disaster and they knew whom they held responsible: “this betrayal was committed by the cursed Genoese of Pera, rebels against the Christian faith,” declared Nicolo Barbaro, “to show themselves friendly to the Turkish Sultan.” The Venetians claimed that someone from Galata had gone to the sultan’s camp with news of the plan. They named names: it was the Podesta himself who had sent men to the sultan, or it was a man called Faiuzo. The Genoese replied that the Venetians had been entirely responsible for the debacle; Coco was “so greedy for honour and glory” that he had ignored instructions and brought disaster on the whole expedition. Furthermore they accused the Venetian sailors of secretly loading their ships and making ready to escape from the city.
A furious row broke out, “each side accusing the other of intending to escape.” All the deeper enmities between the Italians bubbled to the surface. The Venetians declared that they had unloaded their ships again at the command of the emperor and suggested that the Genoese should likewise “put the rudders and sails from your ships in a safe place in Constantinople.” The Genoese retorted that they had no intention of abandoning the city; unlike the Venetians, they had wives, families, and property in Galata “which we are preparing to defend to the last drop of our blood” and refused to put “our noble city, an ornament to Genoa, into your power.” The deep ambiguity of the position of the Genoese at Galata laid them open to charges of deception and treachery from every direction. They traded with both sides yet their natural sympathies lay with their fellow Christians, and they had compromised their overt neutrality by allowing the chain to be fixed within their walls.
A siege tower attacks a castle
It is probable that Constantine had to intervene personally in the quarrel among the suspicious Italians, but the Horn itself remained a zone of unresolved tension. Haunted by the fear of night attacks or a pincer movement between the two arms of the Ottoman fleet, the one inside the Horn at the Springs and the other outside at the Columns, it was impossible for the Christian fleet to relax. Day and night they stood to arms, straining their senses for the sound of approaching fire ships. At the Springs the Ottoman guns remained primed against a second assault, but their ships did not move. The Venetians reorganized themselves after the loss of Coco. A new commander, Dolfin Dolfin, was appointed to his galley and consideration was given to other strategies for destroying the Ottoman ships in the Horn. Evidently another ship-borne assault was considered too risky after the failure of April 28 so the decision was taken to use long-range means to discomfort the enemy.
On May 3 two fairly large cannon were placed by one of the water gates onto the Horn directly opposite the Ottoman fleet at a distance of about 700 yards across the water and proceeded to bombard the ships. Initial results were promising. Some of the fustaewere sunk and “many of their men were being killed by our bombardment,” according to Barbaro, but the Ottomans took swift measures to counter this threat. They moved their ships back out of range and replied with three large cannon of their own “and caused considerable damage.” The two sets of guns blasted away at each other day and night for ten days across the strait, but neither could knock the other out, “because our cannon were behind the walls, and theirs were protected by good embankments, and the bombardment was carried out across a distance of half a mile.” In this way the contest petered away into a stalemate, but the pressure in the Horn remained, and on May 5 Mehmet responded with an artillery initiative of his own.
His restless mind had evidently been considering for some time how to bombard the ships at the boom, given that the walls of Galata lay within the line of fire. The solution was to create a cannon with a more looping trajectory that could fire from behind the Genoese town. He accordingly put his gun founders to work devising a primitive mortar, “that could fire the stone very high, so that when it came down it would hit the ships right in the middle and sink them.” The new cannon had duly been made and was now ready. From a hill behind Galata it opened fire on the ships at the boom. The trajectory was complicated by the walls of the town within the line of fire, but this was probably a positive advantage to Mehmet: it also allowed him to put psychological pressure on the suspect Genoese. As the first shots from the mortar hurtled over their roofs, the townspeople must have felt the Ottoman noose tightening on their enclave. The third shot of the day “came from the top of the hill with a crash” and hit not an enemy vessel but the deck of a neutral Genoese merchant ship “of three hundred botte, which was loaded with silk, wax and other merchandise worth twelve thousand ducats, and immediately it went straight to the bottom, so that neither the masthead nor the hull of the ship were visible, and a number of men on the ship were drowned.” At once all the vessels guarding the boom moved into the lee of Galata’s city walls. The bombardment went on, the range was shortened slightly, and balls started to hit the walls and houses of the town itself. Men on the galleys and ships continued to be killed by the stone bullets, “some shots killing four men,” but the walls afforded sufficient protection to prevent any more ships being sunk. For the first time the Genoese found themselves under direct bombardment, and although only one person was killed, “a woman of excellent reputation, who was standing in the middle of a group of thirty people,” the declaration of intent was clear.
A deputation from the city made its way to the sultan’s camp to complain about this attack. The vizier protested with a straight face that they thought the ship belonged to the enemy and blandly assured them that “whatever they were owed they would be repaid” when the city was finally captured. “With this act of aggression did the Turks repay the friendship which the people of Galata had shown them,” Doukas proclaimed sarcastically, referring to the intelligence that had undone Coco’s attack. Meanwhile stone balls continued to loop down over the Horn in an arced trajectory. By May 14, according to Barbaro, the Ottomans had fired “two hundred and twelve stone balls, and they all weighed at least two hundred pounds each.” The Christian fleet remained pinned down and useless. Well before that date it was clear that the Christians had surrendered effective control of the Horn, and the pressing need to provide more men and materials on the land walls further deepened the divisions among the sailors. With the pressure easing, Mehmet ordered a pontoon bridge to be constructed across the Horn just above the city walls to shorten his lines of communications and to allow men and guns to be moved about at will.
At the land walls Mehmet also set about tightening the screw. His tactics became attritional and increasingly psychological. Now that the defenders had to be spread even more thinly, he decided to wear them down with incessant gunfire. In late April he moved some of the big guns to the central section of wall near the St. Romanus Gate, “because in that place the wall was lower and weaker,” though attention was still also being directed to the single wall in the palace area. Day and night the guns blasted away; occasional skirmishes were mounted at irregular moments to test the resolve of the defense, then suspended for days at a time to lull the defenders into a false sense of security.
Toward the end of April a substantial bombardment brought down about thirty feet from the top of the wall. After dark, Giustiniani’s men set to once again, walling up the breach with an earth bank, but the following morning the cannon renewed their attack. However, toward midday the chamber of one of the big guns cracked, probably because of flaws in the barrel, although the Russian Nestor-Iskander claimed that it had been hit by one of the defenders’ own cannon. Infuriated by this setback, Mehmet called for an impromptu attack. A charge was made at the wall that took the defenders by surprise. A huge firefight ensued. Bells were rung in the city, and people rushed to the ramparts. With the “clatter and flashing of weapons, it seemed to all that the city had been uprooted from its foundation.” The charging Ottoman troops were mown down and trampled underfoot by those coming up behind in their frenzy to reach the walls. To the Russian Nestor-Iskander it was a ghoulish prospect: “as if on the steppes, the Turks walked over the broken human corpses crammed to the top and fought on, for their dead resembled a bridge or a stairway to the city.” With huge difficulty the attack was eventually repulsed, although it took until nightfall. Corpses were left piled in the ditches; “from near the breach to the valleys they were filled with blood.” Exhausted by the effort, soldiers and townspeople retired to sleep, leaving the wounded groaning outside the walls. The following day the monks again started their lugubrious task of burying the Christian dead and counting the number of their fallen enemy. Constantine, now strained by the attritional fighting, was visibly upset by the casualties.
In effect exhaustion, hunger, and despair were beginning to take their toll on the defenders. By early May food supplies were running short; it was now more difficult to trade with the Genoese at Galata and dangerous to row out into the Horn to fish. During quiet spells soldiers at the wall took to deserting their posts in search of food for their families. The Ottomans became aware of this and made surprise raids to drag down the barrels of earth on the ramparts with hooked sticks; they could even openly approach the walls and retrieve cannon-balls with nets. Recriminations mounted. The Genoese archbishop, Leonard, accused the Greeks who had left their posts of being afraid. They replied, “What is the defence to me, if my family’s in need?” Others, he considered, “were full of hatred for the Latins.” There were complaints of hoarding, cowardice, profiteering, and obstruction. Rifts started to open up across the fault lines of nationality, language, and creed. Giustiniani and Notaras competed for military resources. Leonard railed against “what certain people did – drinkers of human blood – who hoarded food or raised its price.” Under the stress of the siege, the fragile Christian coalition was falling apart. Leonard blamed Constantine for failing to control the situation: “the Emperor lacked severity, and those who did not obey were neither punished with words or the sword.” These rifts probably made their way back to Mehmet outside the wall. “The forces defending the city fell into disunity” recorded the Ottoman chronicler Tursun Bey of these days.
To ensure that the walls were not neglected in the search for food, Constantine ordered that supplies should be evenly distributed among the dependants of the soldiers. So serious was the situation that with the advice of his ministers he began to requisition church plate and had it melted down for coin to pay the men so that whatever food was available might be purchased. It was probably a controversial move, unlikely to win the favor of the pious Orthodox who saw the sufferings of the city as a consequence of sin and error.
Deliberations among the commanders intensified. The presence of the enemy fleet in the Horn had greatly confused the defense, and they were forced to reallocate their troops and commands accordingly. The sea was watched from the walls twenty-four hours a day, but nothing stirred on the western horizon. Probably on May 3 a major council was called, involving the commanders, civic dignitaries, and churchmen, to discuss the situation. The guns were still pummeling the walls, morale was weakening, and there was a feeling that all-out assault was imminent. In an atmosphere charged with foreboding, a move was made to persuade Constantine to leave the city for the Peloponnese, where he could regroup, gather new forces, and strike again. Giustiniani offered his galleys for the emperor’s escape. The chroniclers give an emotional account of Constantine’s response. He “fell silent for a long time and shed tears. He spoke to them as follows: ‘I praise and thank your counsel and all of you, as all of this is in my interest; it can only be so. But how can I do this and leave the clergy, the churches of God, the empire and all of the people? What will the world think of me, I pray, tell me? No, my lords, no: I will die here with you.’ Falling, he bowed to them and cried in grief. The patriarch and all of the people present started to weep in silence.”
Recovering from this moment, Constantine made a practical suggestion that the Venetians should send out a ship at once to search the eastern Aegean for signs of a rescue fleet. Twelve men volunteered for the hazardous duty of running the Ottoman blockade, and a brigantine was accordingly prepared for the task. Toward midnight on May 3 the crew, dressed as Turks, stepped aboard the small boat, which was towed to the boom. Sporting the Ottoman flag, it unfurled its sail and slipped unnoticed through the enemy patrol and headed west down the Marmara under cover of darkness.
Mehmet continued to bombard the walls despite technical difficulties with the big guns. On May 6 he decided that the time was right for a knockout blow: “he ordered all of the army to march once more on the city and to make war for all day.” News from within the city probably convinced him that morale was collapsing; other reports may have warned him of the slowly gathering momentum of an Italian relief force. He sensed that the weakness of the central section of wall was now at a critical point. He decided to attempt another major attack.
The big guns opened up on May 6, supported by smaller cannon in the now familiar pattern of firing, accompanied by “cries and the banging of castanets to frighten the people of the city.” Soon another portion of wall fell in. The defenders waited for nightfall to make their repairs, but on this occasion the guns continued firing in the dark. It became impossible to repair the gap. The following morning the cannon again plugged away at the base of the wall and brought down a further substantial section. All day the Ottomans kept firing. At about seven o’clock at night with the customary din, a massive assault was launched at the breach. Away in the harbor the Christian sailors heard the wild cries and stood to arms, fearing a matching attack by the Ottoman fleet. Thousands of men crossed the ditch and ran for the breach, but numbers were not an advantage in the limited space, and they trampled one another in their attempt to force their way in. Giustiniani rushed to meet the intruders, and a desperate hand-to-hand struggle took place in the gap.
In the first wave, a Janissary called Murat led the assault, slashing fiercely at Giustiniani, who was only saved from death by a Greek jumping down from the wall and cutting off his assailant’s legs with an axe. A second wave was led by one Omar Bey, the standard bearer of the European army – and was met by a substantial contingent of Greeks commanded by their officer Rhangabes. In the slashing, hacking confusion, the two leaders squared up to each other in single combat in front of their men. Omar “bared his sword, he attacked him and with fury did they slash at each other. Rhangabes stepped on a rock, grasped his swords with two hands, struck him on the shoulder, and cut him into two, for he had great strength in his arms.” Infuriated at the death of their commander, the Ottoman troops encircled Rhangabes and cut him down. Like a scene from the Iliad, the two sides surged forward to try to seize the body. The Greeks were desperate to gain control of the corpse and piled out of the gates, “but they were unable and suffered many losses.” The Ottomans cut the mutilated body to pieces and drove the Greek soldiers back into the city. For three hours the battle raged on, but the defenders successfully held the line. As the fighting died down, the cannon started to open up again to prevent the breach being filled, and the Ottomans launched a second diversionary raid, trying to set fire to the gate near the palace. This was again defeated. In the darkness Giustiniani and the exhausted defenders worked to rebuild the makeshift defenses. Because of the firing at the wall, they were forced to build their protective barrier of earth and timber slightly inside its original line. The wall was holding – but only just. And inside the city “there was great mourning and dread among the Greeks over Rhangabes, because he was a great warrior, was courageous, and was beloved of the Emperor.”
For the defenders the continuous cycles of bombardment, attack, and repair began to blur. Like diaries of trench warfare, the chroniclers’ accounts become repetitive and monotonous. “On the eleventh of May,” records Barbaro, “on this day nothing happened either at land or at sea except a considerable bombardment of the walls from the landward side, and nothing else worth mentioning happened … on the thirteenth of May there came some Turks to the walls, skirmishing, but nothing significant happened during the whole day and night, except for continuous bombardment of the unfortunate walls.” Nestor-Iskander starts to lose track of time; events jump out of sequence, converge, and repeat. Both soldiers and civilians were growing weary of fighting, repairing, burying corpses, and counting the enemy dead. The Ottomans, with their scrupulous concern for the hygiene of their camp, carried their casualties away and burned the bodies daily, but the ditches were still choked with rotting corpses. The slaughter risked contaminating water supplies: “the blood remained in the rivers and putrefied in the streams, giving off a great stench.” Within the city the people turned increasingly to the churches and the miracle-working power of their icons, preoccupied by sin and the theological explanation for events. “Thus one could see throughout the entire city all the people and the women who came in miraculous procession to the churches of God with tears, praising and giving thanks to God and to the most pure Mother of God.” In the Ottoman camp the hours of the day were marked out by the call to prayer; dervishes went among the troops enjoining the faithful to hold fast and remember the prophecies of the Hadith: “in the jihad against Constantinople, one third of Muslims will allow themselves to be defeated, which Allah cannot forgive; one third will be killed in battle, making them wondrous martyrs; and one third will be victorious.”
As losses continued to mount, Constantine and his commanders hunted anxiously for resources to fill the gaps, but the difficulty of getting all the defenders to cooperate continued to frustrate their best efforts. The grand duke Lucas Notaras quarreled with Giustiniani, while the Venetians largely operated as an independent force. The only supply of untapped manpower and weapons remained on the galleys, and an appeal was made to the Venetian community accordingly. On May 8 the Venetian Council of the Twelve met and voted to unload the arms stored on the three Venetian great galleys, to transfer the men to the walls, and then sink the galleys in the Arsenal. It was a desperate measure designed to ensure the full-hearted involvement of the sailors in the fate of the city, but it provoked another furious backlash. As the unloading was about to begin, the crews leaped to bar the gangways with drawn swords, declaring “let us see who will take the cargoes from these galleys! … we know that once we have unloaded these galleys and sunk them in the Arsenal, at once the Greeks will keep us in their city by plain force as their own slaves, while we are now free either to go or to stay.” Fearing the destruction of their one means of safety, the captains and crews sealed their ships and sat tight. All day bombardment of the land walls continued with unbridled ferocity. The urgency of the situation forced the council to meet again the following day and amend its plans. This time the captain of the two long galleys, Gabriel Trevisano, agreed to disarm his ships and take his 400 men to join the defense at the St. Romanus Gate. It took four days to persuade the men to cooperate and to move the equipment. By the time they arrived on May 13, it was almost too late.
Although Mehmet had concentrated his fire on the area of the St. Romanus Gate, some guns continued to blast away at a spot near the palace where the Theodosian wall formed its awkward junction with the single wall. By May 12 the guns had demolished a section of outer wall and Mehmet decided to make a concentrated night attack on this spot. Toward midnight a huge force advanced on the breach. The defenders were taken by surprise and forced back from the wall by a force commanded by Mustapha, the standard-bearer of the Anatolian army. Further reinforcements rushed from other sections of the wall, but the Ottomans continued to push them back and began to mount scaling ladders against the wall. Terror broke out in the narrow streets around the palace. The townspeople ran fleeing from the wall and many “believed that night that the city was lost.”
At this moment, according to Nestor-Iskander, a grim council of war was taking place three miles away in the porch of St. Sophia. It had become unavoidable to confront the gravity of the situation. The defenders were being relentlessly thinned out day after day: “if it continues on, all of us will perish and they will take the city.” Confronted with this reality, Constantine was laying a series of blunt options before his commanders: they could either sally out of the city at night and try to defeat the Ottomans in a surprise attack or they could sit tight and await the inevitable, hoping for rescue by the Hungarians or the Italians. Lucas Notaras was suggesting that they should continue to hold out, while others were again begging Constantine to leave the city, when word arrived that “the Turks were already ascending the wall and overpowering the townspeople.”
Constantine galloped toward the palace. In the darkness he met citizens and soldiers fleeing from the breach. In vain he tried to turn them back, but the situation was deteriorating by the minute. Ottoman cavalry had started to penetrate the city, and the fighting was now taking place inside the walls. The arrival of Constantine and his bodyguard managed to rally the Greek soldiers: “the Emperor arrived, cried out to his own men, and made them stronger.” With the help of Giustiniani he forced the intruders back, trapped them in the maze of narrow streets, and divided their forces in two. Cornered, the Ottomans counterattacked fiercely, trying to get at the emperor. Unscathed and excited by the chase, Constantine drove some of them back as far as the breach – and would have galloped after them “but the nobles of the imperial suite and his German guards stopped him and prevailed on him to ride back.” The Ottoman troops who could not escape were massacred in the dark lanes. Next morning the townspeople dragged the corpses up to the walls and hurled them into the ditch for their comrades to collect. The city had survived, but each attack was lengthening the odds of survival.
This was to be Mehmet’s last major assault on the palace section of wall. Despite its failure he must have felt that success was within his grasp. He seems now to have decided to concentrate all his firepower on the weakest stretch of all – the St. Romanus Gate. On May 14, when he learned that the Christians had disarmed some of their galleys and withdrawn the majority of their fleet into a small harbor back from the boom, he concluded that his ships in the Horn were relatively safe from attack. He then moved his guns from Galata Hill around to the land walls. At first he stationed them to bombard the wall near the palace; when this proved ineffectual he moved them again to St. Romanus. Increasingly the guns were concentrated at one spot rather than being spread out along a broad front. The bombardments became ever more furious: “day and night these cannon did not stop firing at our poor walls, battering large portions of wall to the ground, and we in the city worked day and night to effect good repairs where the walls were smashed, with barrels and brushwood and earth and whatever else was necessary to do this.” It was here that the fresh men from the long galleys under Trevisano were stationed with “good cannon and good guns and a large number of crossbows and other equipment.”
At the same time Mehmet ensured that the ships defending the boom were kept under constant pressure. On May 16 at the twenty-second hour some brigantines were seen to detach themselves from the main Ottoman fleet out in the straits and head at full speed for the boom. The watching sailors assumed them to be Christian conscripts escaping from the fleet “and we Christians who were at the chain waited them with great pleasure.” As they drew near, however, they loosed shots at the defenders. At once the Italians launched their own brigantines to see them off, and the intruders turned to escape. The Christian ships nearly caught them before “they hurriedly started rowing and escaped back to their fleet.” The following day the Ottomans tested the boom again with five fastfustae. They were seen off with a hail of “more than seventy shots.”
A third and final assault on the boom was mounted before daybreak on May 21, this time by the whole fleet. They came rowing hard toward the chain “with a great sounding of their tambourines and castanets in an attempt to frighten us,” then stopped, eyeing up the strength of their opponents. The ships at the boom were armed and ready and a major sea battle seemed about to unfold when suddenly the alarm was heard from within the city, signaling a general attack. At this, all the ships in the Horn rushed to action stations, and the Ottoman fleet appeared to have second thoughts. It turned about and sailed back to the Double Columns, so that “two hours after sunrise there was complete calm on both sides, as if no attack by sea had taken place.” It was the last attempt on the boom. In all likelihood the morale in the Ottoman fleet, largely manned by Christian rowers, was now too low to mount a serious challenge to the Christian ships, but these maneuvers ensured that the defenders could never relax.
Elsewhere the Muslims were ominously busy. On May 19 Ottoman engineers finished the construction of a pontoon bridge ready to swing across the Horn just beyond the walls. It was another extraordinary feat of improvisation. The pontoons comprised a thousand large barrels, doubtless obtained from the wine-drinking Christians at Galata, tied together in pairs lengthways and planked on top to provide a carriageway wide enough for five soldiers to walk abreast and solid enough to support a cart. The aim was to shorten communications round the top of the Horn between the two wings of his army. Barbaro suggests that Mehmet was preparing the pontoon bridge in readiness for a general attack when he might want to move his men quickly, but that it was only floated into its final position across the Horn at the end of the siege, for “if the bridge had been stretched across the Horn before the all-out attack, a single shot from a cannon would have broken it.” All these preparations could be seen from the city walls. They provided the defenders with an ominous sense of the huge resources of manpower and materials that Mehmet could bring to the siege, but it was engineering work that they could not yet see that was soon to throw the Christians into deeper panic.
By the middle of May Mehmet had stretched the defenses of the city to the limit, but they had still not cracked. He had employed the resources of his army and navy to the full, in assault, bombardment, and blockade, three of the key techniques of medieval siege warfare. There remained one classic strategy as yet largely untried – mining.
Within the Ottoman vassal states in Serbia lay Novo Brdo, the most important city in the interior of the Balkans, famed throughout Europe for the wealth of its silver mines. The Slav troops conscripted for the campaign included a band of skilled miners from the city, probably Saxon immigrants, “masters in the art of digging and cutting away mountains, to whose tools marble was as wax and the black mountains as piles of dust.” They had made an early attempt at mining under the walls in the central section, but this had been abandoned because the ground was unsuitable. In mid-May, as other methods failed and the siege dragged on into its second month, another attempt was started, this time near the single wall of the palace. Mining, although laborious, was one of the most successful techniques for bringing down walls, and had been profitably employed by Muslim armies for hundreds of years. By the end of the twelfth century Saladin’s successors had learned to capture the great crusader castles within six weeks through a combination of bombardment and mining.
Sometime in mid-May the Saxon silver miners, hidden by palisades and bunkers, started to dig the 250 yards to the wall from behind the Ottoman trenches. It was skilled, exhausting work and nightmarishly difficult. Lit by smoking torches, the miners excavated narrow subterranean tunnels, propping them with timber supports as they went. Attempts to undermine the walls in earlier Ottoman sieges had proved unsuccessful, and it was the received wisdom of old men in the city that mining would inevitably fail because the ground beneath the walls was mostly solid rock. In the dead of night on May 16 the defenders were aghast to discover the falsity of this notion. By chance soldiers on the ramparts heard the clink of pickaxes and the sound of muffled voices coming from the ground inside the wall. The mine had evidently passed under the ramparts and was intended to provide a secret point of entry into the city. Notaras and Constantine were quickly notified. A panicky conference was called and a search was made throughout the city for men with mining experience to confront this new threat. The man chosen to organize the defense against attack from underground was something of a curiosity: “John Grant, a German, a skillful soldier, highly trained in military matters,” had come to the siege in the company of Giustiniani. He was in fact a Scotsman who had apparently worked in Germany. It is impossible to guess at the sequence of events that had brought him to Constantinople. He was evidently a highly skilled professional soldier, siege specialist, and engineer, and for a brief moment he occupied a central role in one of the strangest sub-plots in the story of the struggle.
Grant evidently knew his business. The position of the enemy mine was located by the sound of the work. A countermine was dug with speed and stealth. The defenders had the advantage of surprise. Bursting into the enemy tunnel in the dark, they fired the pit props and collapsed the tunnel on the miners, leaving them to suffocate in the dark. The danger posed by this mine banished any complacency within the city. Henceforth, full precautions were taken to watch for mining activity. Grant must have instituted the standard practices of the time. Bowls or buckets of water would have been placed at regular intervals on the ground by the wall and observed for telltale ripples on the surface that would indicate subterranean vibrations. The greater skill was to locate the direction of the mine and to intercept it quickly and stealthily. Over the following days a grim underground struggle unfolded with its own skills and disciplines that echoed the contest for the wall and the boom in the daylight world. For a few days after May 16, Christian sappers found no sign of movement. On the 21st another mine was detected. It had again passed under the foundations with the intention of letting troops into the city. Grant’s men intercepted the tunnel but failed to surprise the Ottomans, who withdrew, burning the props behind them so that it collapsed.
Thereafter it became a game of cat and mouse fought out in the dark under horrific conditions. The following day “at the hour of Compline” the defenders discovered a tunnel into the city near the Calegaria Gate, which they intercepted. They burned the miners alive with Greek fire. A few hours later telltale vibrations indicated yet another mine nearby, but this one proved harder to intercept. However, the pit props collapsed of their own accord and killed all the miners inside.
The Saxon miners were indefatigable. Not a day went by without underground warfare. Each time, Giacomo Tetaldi recalled, “the Christians dug counter-mines, and listened, and located them … they suffocated the Turks in their mines with smoke, or sometimes with foul and evil-smelling odours. In some places they drowned them with a flood of water, and often found themselves fighting hand to hand.”
While the tunneling continued, Mehmet’s engineers contrived another remarkable and totally unexpected initiative in the world above. At daybreak on the morning of May 19, the watchers on the wall near the Charisian Gate, stirring themselves for another day, looked out over the distant sea of enemy tents – and were staggered by what they saw. Ten paces in front of them and positioned on the lip of the ditch was an enormous tower, “overtopping the walls of the barbicans,” that had somehow appeared from nowhere overnight. The defenders were amazed and mystified by how the Ottomans had managed to erect this structure so rapidly, which had been wheeled forward from the enemy lines in the dark and now overtopped the ramparts. It was built on a framework of stout beams covered with camel skins and a double layer of hurdles to protect the men inside. Its lower half had been filled with earth and embanked with earth on the outside “so that shots from cannon or handguns could not harm it.” Each story inside was connected by ladders that could also be used to bridge the gap between the tower and the wall. Overnight a huge body of men had also constructed a covered causeway from it back to the Ottoman lines “half a mile long … and over it two layers of hurdles and on top of them camel skins, by means of which they could go from the tower to the camp under cover, in such a way that they could not be harmed by bullets or crossbow bolts or by stones from small cannon.” Armed men rushed to the wall to view the incredible sight. The siege tower was almost a throwback to the era of classical warfare, though it seemed to Archbishop Leonard to be a device “such as the Romans could scarcely have constructed.” It had been designed specifically to fill in the troublesome ditch in front of the wall. Inside the tower, teams of men were excavating earth and hurling it out through small openings in the protective screen into the ditch in front. They kept at it all day while from the higher stories archers shot a covering fire of arrows into the city, “it seemed, from sheer high spirits.”
It was a signature project for Mehmet – conceived in secret on a grand scale and executed, like the transportation of the ships, with extraordinary speed. Its psychological impact was profound. The resourcefulness and the resources of the besieging army must have struck the defenders like a recurring nightmare. Constantine and his commanders hurried to the battlements to confront yet another emergency, “and when they saw it they were all struck down with fear like dead men, and they were continuously concerned that this tower might cause them to lose the city because it overtopped the barbicans.” The threat from the tower was palpable. It was closing up the ditch in front of their eyes, and the covering fire from its archers made it difficult to mount any response. By nightfall the Ottomans had made remarkable progress. They had filled the ditch with logs, dried branches, and earth. The siege tower, pushed from within, moved farther forward and closer to the wall. The panicky defenders decided that immediate action was imperative – another day under the shadow of the overhanging tower could prove fatal. After dark, packed barrels of gunpowder were prepared behind the walls and rolled off the ramparts toward the tower, with fuses sputtering. There was a series of huge explosions: “suddenly the earth roared like great thunder and lifted up the siege turrets and the men to the clouds, like a mighty storm.” The tower cracked and exploded: “people and logs fell from high.” The defenders hurled barrels of burning pitch down on the wounded groaning below. Advancing out from the walls they massacred any further survivors and burned the bodies along with other siege equipment that had been drawn up nearby: “long battering rams and wheeled ladders, and waggons with protective turrets on them.” Mehmet observed this failure from a distance. Furious, he withdrew his men. Similar towers which had been advanced at other points along the wall were also withdrawn or burned by the defenders. The siege towers were evidently too vulnerable to fire, and the experiment was not repeated.
Underground the tunnel war intensified. On May 23 the defenders detected and entered yet another mine. As they advanced down the narrow shaft by the flickering light of flares, they found themselves suddenly face-to-face with the enemy. Hurling Greek fire, they brought down the roof, burying the miners, but managed to capture two officers and bring them back to the surface alive. The Greeks tortured these men until they revealed the location of all the other workings; “and when they had confessed, their heads were cut off, and their bodies were thrown from the walls on the side of the city where the Turkish camp was; and the Turks, when they saw their men thrown from the walls, became enraged and felt great bitterness towards the Greeks and us Italians.”
The following day the silver miners changed their tactics. Instead of passing straight under the walls to create passageways into the city, they turned their tunnel sideways on reaching the wall to run directly under it for a distance of ten paces. The tunnel was propped on timbers and prepared for firing with the aim of collapsing a section of wall. The work was only just discovered in time; the intruders were repulsed and the wall was bricked up again underneath. It caused great disquiet in the city. On May 25 one last attempt was made to repeat this operation. The miners again managed to prop a long section of wall ready for firing before being intercepted and repulsed. In the eyes of the defenders it was the most dangerous of any of the tunnels to be found, and its discovery signaled the end of the tunnel war. The Saxon miners had worked ceaselessly for ten days; they had constructed fourteen tunnels, but Grant had destroyed them all. Mehmet acknowledged the failure of both towers and mines – and kept the guns firing.
Away to the west of Constantinople, far from the sound of firing and the night attacks, another small but significant drama was being played out. In one of the island harbors of the eastern Aegean a sailing ship was rocking at anchor. It was the Venetian brigantine that had slipped away from the city. During mid-May it swept the archipelago, looking for signs of a rescue fleet. The crew found nothing. They had received no positive reports from passing vessels. They now knew that there were no ships. In fact the Venetian fleet was off the coast of Greece cautiously seeking information about Ottoman naval intentions, while the galleys that the pope had ordered from Venice were still under construction. The crew fully understood the implications of their situation. On deck a heated debate was in progress about what to do next. One sailor made a strong case for sailing away from the city and back to “a Christian land, because I know very clearly that by this time the Turks will have taken Constantinople.” His companions turned to him and replied that the emperor had entrusted them with this task, and that it was their bounden duty to complete it: “and so we want to return to Constantinople, if it is in the hands of the Turks or the Christians, if it is to death or to life, let us go on our way.” The democratic decision was taken to return, whatever the consequences.
The brigantine swept back up the Dardanelles on the south wind, reassumed its Turkish disguise, and approached the city shortly before daybreak on May 23. This time the Ottoman fleet was not deceived. They had been patroling attentively, fearing the arrival of Venetian galleys and took the small sailing boat for their outrider. They rowed forward to intercept, but the brigantine outstripped them and the boom opened to let it back in. That day the crew went to make their report to the emperor that they had found no fleet. Constantine thanked them for returning to the city and “began to weep bitterly for grief.” The final realization that Christendom would send no ships snuffed out any hopes of rescue; “and seeing this the Emperor decided to put himself in the hands of our most merciful Lord Jesus Christ and of his Mother Madonna Saint Mary, and of Saint Constantine, Defender of his City, that they might guard it.” It was the forty-eighth day of the siege.