In early April, while the big guns were busy pounding the land walls, Sultan Mehmet began to deploy the fleet, his other new weapon, for the first time. He had been quick to grasp a fact obvious to all potential besiegers from the time of the Arabs onwards – that without firm control of the sea an attempt on the city was likely to fail. His father Murat had come to the siege of 1422 with no ability to strangle Byzantine sea-lanes – the Ottoman fleet had been caught and destroyed at Gallipoli by the Venetians six years earlier. Without a blockade of the Bosphorus and the Dardanelles the city could be easily resupplied by the Greek cities of the Black Sea or by Christian sympathizers from the Mediterranean basin. It was with this in mind that the Throat Cutter had been built and equipped with heavy guns in the summer of 1452. No ship could henceforth pass up or down the Bosphorus into the Black Sea unexamined.
At the same time he had set to work repairing and strengthening the navy. During the winter of 1452 an ambitious programme of shipbuilding work was undertaken at the Ottoman naval base at Gallipoli and probably at Sinop on the Black Sea and other shipyards on the Aegean coast. According to Kritovoulos, Mehmet ‘thought that the fleet would be more influential in the siege and the fighting ahead than the army’, and gave great personal attention to this work. The empire had acquired an experienced resource of shipwrights, sailors and pilots, both of Greek and Italian origin, as it rolled up the coasts of the Black Sea and Mediterranean, and this skilled manpower could be brought into play in naval reconstruction. Mehmet also had access to the substantial natural resources essential to naval endeavour: timber and hemp, cloth for sails, cast iron for anchors and nails, pitch and tallow for caulking and greasing hulls. These materials were sourced widely from within the empire and beyond. It was the logistical skill of Mehmet to bring together all these resources for war.
As with cannon, the Ottomans were swift to adopt the ships of their Christian enemies. The key fighting vessel of the Mediterranean Middle Ages was the oared galley, the natural successor of the Roman and Greek galleys of classical antiquity, a vessel that dominated the Mediterranean in evolving forms from the start of the Bronze Age until the seventeenth century, and whose basic shape, echoed on Minoan seals, Egyptian papyri and the pottery of classical Greece, was to be as central to the sea’s history as the vine and the olive tree. By the late Middle Ages the prototype war galley was long, fast and very lean, typically perhaps 100 feet in length, under twelve feet in width with a raised prow or spur at the front to act as a fighting platform or boarding bridge onto enemy ships. The tactics of naval warfare were hardly distinguishable from those on land. The galleys would be packed with a complement of fighting men who, after an initial discharge of missiles, would attempt to storm the opposing vessel in vicious hand-to-hand combat.
The galley itself was startlingly low in the water. To maximize the mechanical advantage of the oars, a laden war galley might have clearance above the water of two feet. It could be powered by sail, but it was the oars that gave the galley its punch and flex in battle. The rowers were arranged in a single tier, above deck – which left them horribly exposed in battle – and usually two or three to a side on a single bench; each man worked an individual oar whose length was determined by his place on the bench. Conditions were cramped; galley rowing meant operating an oar in the seat space of a modern passenger plane so that the basic rowing motion, where sideways space was at a premium, involved the oarsman pushing the oar straight forward with his elbows kept in and rising up out of his seat in the process, then dropping back into it. Not surprisingly galley rowing required skilled crews able to row in perfect time – and considerable muscle power to work an oar up to thirty feet long weighing some 100 pounds. The war galley was bred for speed and manoeuvrability in battle; a galley with a well-greased keel could maintain a dash speed of seven and a half knots for twenty minutes under human power. The demand to row for longer than an hour quickly tired the crew.
For all its pace on a calm sea, the galley suffered from extraordinary disadvantages. The low freeboard rendered it surprisingly unseaworthy, even in the short choppy seas of the Mediterranean, so that galley sailing tended to be confined to the summer months and dictated a preference for hugging the coast to making long journeys over open water. Galley fleets were not infrequently swamped by unseasonal storms. The sails were only useful with the wind full astern, and the oars themselves were useless against any strong headwind. In addition the requirement for speed had created a hull that was fragile and so low in the water as to be at a serious disadvantage when attacking a high-sided vessel, such as a merchant sailing ship or one of the taller Venetian great galleys. The galley’s strengths and weaknesses were to be severely tested in the struggle for the city.
Mehmet had assembled a substantial fleet. He repaired and recaulked older vessels and built a number of new triremes – galleys with oars grouped in threes – as well as smaller scaled-down raiding galleys, ‘long ships, fast and fully decked, with thirty to fifty rowers’, which Europeans called fustae. He appears to have supervised much of this work himself, choosing ‘skilled seamen from all the Asian and European coasts – oarsmen with particular skills, deckhands, helmsmen, commanders of triremes, captains and admirals, and the other ships’ crews’. Some of this fleet was already in the Bosphorus in March, ferrying troops across the straits, but it was not until the start of April that the main force could be assembled at Gallipoli under his appointed admiral Baltaoglu, ‘a great man, a skilful admiral experienced in sea warfare’. It was the first time in seven sieges that the Ottomans had brought a fleet to the city. It was a crucial development.
Gallipoli, ‘homeland of defenders of the faith’, was a talismanic city for the Ottomans and an auspicious point of departure. It was here that they had gained their first foothold in Europe in 1354 after a fortuitous earthquake. The fleet, fired with zeal for holy war and the enterprise of conquest, started out from the Dardanelles and began to work its way up the Sea of Marmara. The crews apparently set out ‘with cries and cheering and the singing of rowing chants, encouraging each other with shouts’. In practice the enthusiasm may have been more muted: a substantial portion of the rowing force were in all likelihood Christians working under compulsion. According to a later chronicler ‘the wind of divine help pushed them forward’, but the reality must have been different. By now the prevailing wind was blowing from the north so the passage up the Marmara had to made against wind and current. The 120 miles to Constantinople presented a hard slog for the galleys. News of their progress preceded them up the sea-lane with a mixture of astonishment and panic. As with his army Mehmet understood the psychological value of superior numbers. It was the impression of a sea covered with oars and masts that appalled the watching Greek villages along the coast. The most reliable estimates of the Ottoman navy were made by experienced Christian seafarers, such Giacomo Tetaldi and Nicolo Barbaro, rather than by more impressionable landlubbers. Between them they estimated a fleet of something between twelve and eighteen full war galleys composed of a mixture of triremes and biremes, then seventy to eighty smaller fustae, about twenty-five parandaria – heavy transport barges – and a number of light brigantines and other small message boats, a force of about 140 boats in all. It was an awesome sight to glimpse over the curve of the western horizon.
Word of Mehmet’s impressive naval preparations reached the city long before his ships, so that the defenders had time to draw up their naval plans with care. On 2 April they closed the Golden Horn with the great chain to create a secure anchorage for their ships and to seal off the puny sea walls from attack. It was a practice embedded deep in the history of the city. As early as 717 a chain had been strung across the strait to hamper besieging Muslim navies. On 6 April, according to Barbaro, ‘we put ready for battle the three galleys from Tana and the two narrow galleys’, and their crews then progressed the length of the land wall in a show of military strength. On the 9th all the naval resources available to the defenders in the harbour were organized and made ready. It was a mixed collection of craft, brought together for a range of motives. There were ships from the Italian city-states and their colonies – Venice, Genoa, Ancona and Crete – as well as a Catalan ship, one from Provence, and ten Byzantine craft. There were galleys of various sizes including the three ‘great galleys’, the bulk carriers of Italian maritime trade, slower than conventional war galleys but stoutly built with higher sides, and two ‘narrow galleys’, slender hulled and low in the water. The majority of the vessels at anchor in the Golden Horn in early April 1453 were merchant sailing ships – high-sided, sail-driven ‘round ships’ – carracks with high poops and sterns, stoutly timbered and masted. In theory none of these were fighting ships, but in the dangerous, pirate-threatened waters of the Mediterranean, the distinction was a fine one. Their height and the vantage points of their decks and crow’s nests gave them natural advantages over low-slung war galleys if supplied with weapons and skilled troops. At this snapshot moment in the history of naval warfare the sailing ship could often hold its own against the most determined attack. Galley-mounted guns were in their infancy; they were too small and mounted too low to threaten a carrack. It was to be another fifty years before the Venetians devised an effective ship-killing gun that could be mounted on a galley. Furthermore, the sailors from Venice and Genoa in particular, who depended totally on their prowess at sea for survival and prosperity, approached all maritime matters with supreme confidence. They made their plans accordingly.
On 9 April therefore, they drew their ten largest merchantmen up in front of the boom ‘in close array and with bows forward’. Barbaro faithfully recorded their captains and the size of each one, ranging from that of Zorzi Doria of Genoa, ‘2,500 botte’, to one of ‘600 botte’; three he named: the Filomati and Guro of Candia, the Gataloxa of Genoa. Alongside these were stationed the stoutest of the galleys. The ships, which were ‘well armed and in excellent order, as if they wanted to join battle, and all equally good’, spanned the length of the boom from the city to Galata on the other side. In the inner harbour a further seventeen square-rigged merchantmen were kept in reserve, together with more galleys, including five of the emperor’s which were probably disarmed to provide a concentration of equipment at the boom. A few surplus ships were scuttled to lessen the risk of being hit by cannon and spreading fire, the waking nightmare of mariners in a closely packed fleet. Secure in both their defences and their nautical skill, with cannon positioned on the foreshore as an extra assurance, the captains sat to await the arrival of the Ottoman fleet. They had perhaps thirty-seven ships in total against an armada of 140, on paper a huge discrepancy, but the Italian seafarers understood the critical issues in sea warfare. Ship handling was a craft skill dependent on well-trained crews, so that the outcome of naval encounters rested less on numbers than on experience, determination and the random luck of winds and currents. ‘Seeing that we had such an impressive fleet, we felt ourselves confidently secure against the fleet of the infidel Turks,’ recorded Barbaro smugly, betraying a consistent Venetian tendency to underestimate Ottoman maritime skills.
The Ottoman fleet was finally sighted on 12 April at about one o’clock in the afternoon, battling up against the north wind. Doubtless the sea walls were crowded with watching citizens as the horizon slowly filled with masts. The fleet came rowing on ‘with determination’, but seeing the Christian ships drawn up at the boom in line of battle, it went over to the other side of the strait, lining the opposite shore. It made a strong impression on those watching and deepened the city’s gloom, hearing the ‘eager cries and the sound of castanets and tambourines, with which they filled our fleet and those in the city with fear’. Later in the afternoon, the whole fleet moved two miles further up the Bosphorus to a small harbour on the European shore called by the Greeks the Double Columns, now the site of the Dolmabache Palace. The size and power of the warlike fleet had undoubtedly dented the confidence of even the Italians, because the ships at the boom stood to arms all that day and into the night ‘waiting hour after hour in case they came to attack our fleet’, but nothing happened. It was to be the start of an attritional game of cat and mouse. To minimize the risk of being surprised, two men were stationed permanently on the town walls of neutral Galata from which vantage point the fleet at the Double Columns further up the Bosphorus could be closely watched. At any sign of movement along the straits by even a single ship, a man hurried back down the streets of Galata to the Horn to alert Aluvixe Diedo the harbour commander. The battle trumpet was sounded and those on the ships stood immediately to arms. In this state of nervy apprehension they waited day and night, rocking gently at anchor in the calm waters of the Horn.
Mehmet had three clear objectives for his new fleet: to blockade the city, to attempt to force a way into the Horn, and to oppose any relieving fleet that might sail up the Marmara. Initially Baltaoglu did nothing more than send out patrols round the waters of the city specifically to prevent ships entering or leaving the two small harbours on the Marmara side of the city. At about the same time a further detachment of ships came from the Black Sea laden with cannon balls and other munitions for the army. The arrival of these supplies seemed to precipitate a new cycle of activity in the Ottoman camp.
Impatient to tighten his stranglehold on the city, Mehmet ordered Baltaoglu to make an attempt on the boom. If the Ottomans could force their way into the Horn, Constantine would be compelled to strip the land wall of much-needed defenders to guard the shoreline. Both sides had made careful preparations for this moment. Doubtless at the instigation of Mehmet, whose appetite for artillery innovations was boundless, the Ottomans loaded small cannon onto their galleys. They packed the fighting beaks with heavy infantry and provisioned the vessels with stocks of weapons: stone cannon balls, arrows, javelins and inflammable material. The lookouts on the Galata walls closely observed these preparations, so that Lucas Notaras, the commander of the Byzantine ships, had ample time to prepare the big merchant carracks and galleys with men and ammunition.
Probably on 18 April, at the same time as the first major assault on the land walls at the St Romanus Gate, Baltaoglu launched the new navy’s first attack. Putting out in force from the Double Columns, the fleet rounded the point and advanced at speed towards the boom. They rowed hard at the steady line of tall ships anchored in front of the chain, with the crews encouraging each other with shouts and battle cries. They came on to within a bowshot, then slowed and released a volley of fire from bows and cannon; stone balls, metal bolts and flaming arrows whistled across the water and swept the enemy decks. After the initial salvoes, they came on again towards the anchored ships. As they clashed, the Ottomans attempted the standard boarding procedures of close engagement. Grappling hooks and ladders were thrown up as they tried to scale the sides of the taller ships; attempts were made to slash the merchantmen’s anchor cables. A hail of javelins, pikes and spears was hurled at the defenders. The ferocity of the assault was unquestionable but the advantage of battle lay with the higher and more stoutly built carracks. Stone balls from the ship-mounted cannon of the Ottoman galleys were too small to inflict damage on the sturdy wooden hulls, and the sea-borne soldiers were attacking from below, like troops trying to storm the land walls from the bottom of a ditch. The sailors and marines on board the Christian ships could hurl down missiles from the bow and stern platforms and from higher up in the crow’s nests. Volleys of gads – iron javelins with stabilizing fins – arrows and stones were rained down on the undefended attackers scrabbling at the sides of the ships, ‘wounding many, and killing a considerable number too’. The merchantmen were practised and equipped for close combat at sea; jars of water were at hand to extinguish incendiary devices and simple rope hoists extending from their masts allowed them to swing out heavy stones clear from the sides of the ships and drop them onto the fragile shells of the swarming long boats, ‘and inflicted considerable damage in this way’. The struggle to capture and to protect the chain was intense, but eventually the Christians started to prevail. They manage to turn the flank of the galley fleet. Fearing humiliation Baltaoglu withdrew his ships and sailed back to the Double Columns.
The first round of naval warfare had gone to the defenders. They understood their ships well and a basic fact of naval warfare: that a well-prepared merchantman could hold its own against a swarm of low-lying galleys if the crew were disciplined and well equipped. Mehmet’s hopes for artillery power had not been met at sea. The guns that could be mounted on light-framed galleys were too small to be effective against the stout sides of sailing ships, and the conditions of operation – the difficulty both of preventing the powder absorbing atmospheric moisture at sea and of aiming effectively on a pitching deck – further decreased the chances of success. By the morning of 19 April, Mehmet’s troops had been repulsed by both land and sea, while the spirits of the defenders remained undaunted. The lengthening timeframe of the siege increased Mehmet’s impatience day by day – and the possibility of aid from the West.