The Art of Renaissance Warfare

From The Fall of Constantinople to the Thirty Years War

Stephen Turnbull

• Publisher: Frontline Books
• Year: 2018
• ISBN:
  9781526713773
• Topic: History
• Subtopic: Military & Maritime History
• Index: History

A history of the evolution of military technology among knights in Renaissance Europe from the fifteenth century to the seventeenth century. The Art of Renaissance Warfare tells the story of the knight during the fifteenth and sixteenth centuries—from the great victories of Edward III and the Black Prince to the fall of Richard III on Bosworth Field. During this period, new technology on the battlefield posed deadly challenges for the mounted warrior; but they also stimulated change, and the knight moved with the times. Having survived the longbow devastation at Crécy, Poitiers and Agincourt, he emerged triumphant, his armor lighter and more effective, and his military skills indispensable. This was the great age of the orders of chivalry and the freemasonry of arms that bound together comrades and adversaries in a tight international military caste. Men such as Bertrand du Guesclin and Sir John Chandos loom large in the pages of this book—bold leaders and brave warriors, imbued with these traditions of chivalry and knighthood. How their heroic endeavors and the knightly code of conduct could be reconciled with the indiscriminate carnage of the "chevauchee" and the depredations of the "free companies" is one of the principal themes of this informative and entertaining book.

Chapter 1

A Tale of Two Cities

Even though the fall of Constantinople is no longer seen as a strict dividing line between the Middle Ages and the Renaissance, the events of 1453 are of fundamental importance if the process of transition is to be properly understood. Central to that understanding is a need to place its military significance into its proper context. It is not enough simply to demonstrate that Ottoman artillery shattered the medieval walls of Constantinople, because if this success was indeed the herald of a military revolution then an explanation also has to be offered for the failure of the same army under the same commander with same weapons at a similar city three years later. The experience of the Siege of Belgrade in 1456 therefore makes any discussion of Constantinople into a tale of two cities, not just the one.

Sailing to Byzantium

In spite of the significance loaded on to the loss of Constantinople, it has first to be recognised that by 1453 the ‘New Rome’ of Constantine the Great was no longer the power it had once been. Its influence, and indeed its territory, had shrunk to almost nothing beyond the land that was enclosed within the city’s still-mighty walls, from which communication had to be made almost entirely by sea. Everything immediately across the Bosphorus was already in Ottoman hands, and their capital of Edirne (formerly Adrianople), captured in 1361, actually lay to the west of Constantinople, in Thrace. In terms of surface area there was not much left either to capture or to care about, an attitude that was reflected in the paltry concern that was voiced about the city’s fate prior to its taking. Because Constantinople had once been sacked by the armies of fellow Christians during the Fourth Crusade of 1204, the tendency in western Europe was to look upon the Byzantine Empire as an embarrassing elderly relative who was taking a long time to die.

The fall of Constantinople in 1453 was therefore no sudden event but an act long foreseen and lamented most widely in those lands where the least effort was made to avert it. Contemporary observers of a cynical yet religious mind may well have speculated that, so far, God had spared the city more for the holy relics it contained than for anything else. In reality the attitude towards Constantinople’s fate was expressed most acutely in the reluctance of anyone to come to the city’s assistance, relics or not. To those of an optimistic and romantic inclination Constantinople was still a symbol of eternal Rome. It had withstood numerous sieges in the past and surely would continue to do so. As recently as 1422 an Ottoman force employing artillery had been beaten off by a citizens’ army inspired by a vision of the Virgin Mary on Constantinople’s walls.1

Linked to this touching belief in the capacity of the city’s mighty fortifications to withstand changing military technology was a contempt for, and an underestimation of, the fighting power of the Ottomans – a delusion that was to last for centuries after the fall of Constantinople.2 At a conference held in Florence in 1439 Byzantine officials of the Emperor John VIII estimated that it would take only one month for a crusading army to conquer Turkish-held territory in Europe, and one further month to take the Holy Land!3 In an oration delivered in Rome in 1452, Aeneas Sylvius, who afterwards became Pope Pius II, appealed to his audience to recognise that ‘the Turks were unwarlike, weak, effeminate, neither martial in spirit nor in counsel; what they have taken may be recovered without difficulty’.4

Yet somehow these optimistic attitudes towards going on crusade to assist Constantinople and throw back the ‘weak and effeminate’ Ottomans were never actually translated into action. The experience of Nicopolis in 1396, a Christian disaster brought about by the self-same ‘unwarlike’ Ottomans, had been a very painful one. From that time onwards, whenever crusades to save Constantinople were discussed, one common feature that always prevented them from happening was a serious overestimation of the numbers of Christian princes who would be willing to participate. Philip the Good, Duke of Burgundy from 1419 to 1467, was one of the few European rulers who even contemplated sending a force to confront the Turks, but he was after all the perfect crusader. Philip had been born in 1396, the year of the Nicopolis crusade that had been organised by his grandfather Philip the Bold and led by his father John the Fearless, and he maintained throughout his life a keen interest in this manifestation of knightly virtue.5

Also, unlike many other potential crusaders, Philip the Good’s knowledge of the lands of the infidel was based on sound intelligence. In 1421 he sent a certain Guillebert de Lannoy on a grand tour which included Constantinople, Russia, Rhodes, Jerusalem and Crete. Much of the information Guillebert brought back was in the form of military observations of the balance of power on the Muslim frontier and details of the fortresses that guarded it.6 Intelligence notwithstanding, a crusading expedition remained an exercise on paper until 1441, when a Burgundian fleet set sail for the Mediterranean under the command of Geoffroy de Thoisy. The ships were not primarily intended to assist Constantinople but were instead a response to an appeal for help from the Knights of the Order of Hospitallers of St John of Jerusalem on the island of Rhodes, who were under threat from the Mamluks of Egypt. De Thoisy’s fleet was already cruising the Mediterranean when a request for assistance from the Byzantine emperor was received in Burgundy. In response, further ships were hired in Venice and in 1444 these followed the existing fleet to support an advance against the Ottomans by a largely Hungarian army. The Burgundian fleet was given the small but important role of preventing the Ottomans from crossing the Bosphorus at its northern, Black Sea, end. A combination of bad weather and Ottoman artillery fire neutralised their presence and allowed the Ottomans to engage the Christian army at Varna, where the crusaders were annihilated in the biggest disaster since Nicopolis.

The result was that when Emperor John VIII passed away in October 1448 it looked very much that his successor would be isolated when he faced the greatest challenge in the Byzantine Empire’s long history. There were some minor stirrings to the contrary. In early May 1451 the news of Mehmet II’s plans for taking Constantinople reached Mons, where Philip the Bold’s Knights of the Golden Fleece were gathering for their annual celebration. It was the perfect setting for chivalric plans to be laid so, full of enthusiasm, Philip despatched ambassadors to France, Austria, England and Hungary proposing a grand crusade to save Constantinople. There was a modest reaction, but by March 1453 Philip’s own commitment was weakening because rebels in his own territories demanded attention. So in May 1453, when Mehmet II was setting up his siege lines around Constantinople, Philip the Good was to be found at Ghent, performing a similar operation against enemies of his own.

The Fall of Constantinople

The city that had been founded in AD 324 by Emperor Constantine to be his new capital lay on the shore of the Sea of Marmara where it was entered by the Bosphorus, the strait that leads up to the Black Sea. Now known as Istanbul, it was built on a formidable triangular promontory and was defended to the north by the natural harbour known as the Golden Horn. The weakest point of its natural defences was the landward side, so this area was defended by some of the finest fortifications that the medieval world could provide. The largest section, known as the Walls of Theodosius, dated from the fifth century AD and had withstood sieges for almost one thousand years (see plate 1). It stretched roughly from north to south with a total length of about four miles and consisted of an outer and inner wall. These strong, if old-fashioned walls were joined to the sea walls that encircled the city to make a complete defensive system. Although repairs were made to the walls following the siege of 1422, nothing had been done to convert them to withstand the new challenges that mid-fifteenth-century siege cannon could now provide. The economic plight of isolated Constantinople probably rendered the expense unthinkable.7

The great Siege of Constantinople was conducted personally by the Ottoman Sultan Mehmet II, known to posterity as Mehmet the Conqueror, a military genius who was to be revered as one of the greatest sultans of his line and whose devotion to the military calling was noted by his contemporaries.8 A meticulous planner, he took interest in the minutest details of operations and is described as sketching plans of the city and the location of his cannon and siege engines. Every aspect of the siege operation was known to him, and influenced by him, for months before he came within sight of Constantinople’s walls. His existing strategy of isolating the city from all sides was transferred to the micro level with the taking of all the remaining Byzantine possessions on the Black Sea coast, and most important of all he was determined to have full command of the sea. During previous sieges Constantinople had been able to continue receiving supplies by ship, and as recently as the Varna campaign the Turkish army had depended upon Genoese help to cross the Bosphorus. Steps were now taken to make both these factors irrelevant in the campaign that lay ahead.

On the Asiatic shore of the Bosphorus lay an Ottoman fortress called Anadolu Hisar. In 1452 Mehmet II built a castle opposite it on the European side of the straits. Named first ‘the cutter of the straits’ or ‘the cutter of the throat’, and later simply as Rumeli Hisar ‘the European castle’, the new fortress allowed the Ottoman artillery to control all shipping in and out of the Black Sea in a way that was never before possible. In November 1452 a Venetian galley was sunk by a cannonball fired from Rumeli Hisar. The days of relief armies arriving by sea were over.

In March 1453 an Ottoman fleet assembled off Gallipoli and sailed proudly into the Sea of Marmara while an army assembled in Thrace. This time there were no Burgundian vessels to hinder the ships’ progress, and the sight from Constantinople of the Ottoman navy passing its sea walls while the army approached its land walls was one that struck terror into the inhabitants. To add to the lesson already delivered from Rumeli Hisar concerning the potential of the Ottoman artillery, there soon lumbered into view a tremendous addition to their fire power.

In almost every account one reads of the fall of Constantinople a great emphasis is placed on the part played by artillery.9 Early in his reign Mehmet II had ordered his foundries to experiment in producing large cannon. Although he was not the great innovator in artillery that earlier admirers claimed for him, Mehmet II was an enthusiast for the subject, and appreciated quite early on that siege cannon would be a very important resource in his future plans. He had long immersed himself in illustrated western works on fortifications and siege engines, and was well served by European advisers, whose presence was to lead to accusations that the sultan managed to capture Constantinople because of Christian treachery. A well-known story (recounted originally by the chronicler Dukas) tells how a Hungarian artillery expert named Urban approached the Byzantine emperor with an offer to cast guns for the defence of the city.10 Because the price he demanded was too high, and a supply of raw materials could not in any case be guaranteed, he was sent away disappointed. Urban therefore deserted the Byzantine cause and immediately turned to the sultan, who cross-questioned him, asking if Urban could cast a cannon capable of breaching the walls of Constantinople. When Urban replied that he could cast a cannon capable of destroying the walls of Babylon, Mehmet II hired him for four times the fee he had originally asked at Constantinople.

Within three months Urban had produced the large-calibre weapon that was mounted on Rumeli Hisar and carried out the sinking noted above. This demonstration was so impressive that Mehmet II ordered Urban to build a gun twice the size of the first that could breach the land walls. The resulting monster needed fifty yoke of oxen to move it, and required a total ‘gun team’ of 700 men. It was cast at Edirne and was test fired where:

. . . public announcements were made . . . to advise everyone of the loud and thunderous noise which it would make so that no one would be struck dumb by hearing the noise unexpectedly or any pregnant women miscarry.11

The noise was heard for miles around. The cannonball travelled for a mile and sank almost six feet into the earth when it landed. Urban’s big gun and other smaller pieces were then laboriously dragged to Constantinople by seventy oxen and ten thousand men.

Following the advice of his artillerymen, the sultan positioned his siege guns against the weakest and most vulnerable parts of the wall. The targets included the imperial palace of Blachernae at the north-western corner of the city and the Romanus Gate (now the Topkapi Gate) in the middle wall. The bombardment, which was to last fifty-five days, soon began to cause massive destruction, and the chronicler Kritovoulos has left a fascinating description of what happened when one of the enormous stone balls hit its target:

And the stone, borne with enormous force and velocity, hit the wall, which it immediately shook and knocked down, and was itself broken into many fragments and scattered, hurling the pieces everywhere and killing those who happened to be nearby.12

From the Byzantine side the defenders hit back with their own artillery weapons, but they faced several problems, one of the most serious being that the flat roofs of the towers in the medieval walls were not sufficiently strong to act as gun emplacements. As Leonard of Chios noted, the largest cannon had to remain silent for fear of damage to their own walls by vibration, and Chalkondylas even wrote that the act of firing cannon did more harm to the towers than did the Ottoman bombardment.13 As a consequence they were unable to use their cannon effectively. The sultan, by contrast, had the leisure to mount his bombards in the places where they would do the maximum destruction, and thereby achieved results that under any other circumstances would have been regarded as most unlikely. It was therefore the careful use of artillery, not merely its possession, which was to be such a crucial factor at Constantinople.

On 20 April there occurred one of the few pieces of good fortune which the defenders experienced during the entire siege, when three supply ships braved the Ottoman blockade and entered the Golden Horn. This natural harbour, across which a stout chain had been slung, was the only sea area that the Byzantines still controlled. But two days later the defenders’ elation turned to despair when Mehmet II put into motion an extraordinary feat of military engineering. A wooden roadway was constructed from the Bosphorus to a stream called the Springs, which fed the Golden Horn, and with much muscular effort some eighty Ottoman ships were dragged overland and relaunched far beyond the boom.

Seaborne attacks could now be mounted from much closer quarters, but there were rumours concerning the approach of a relieving army from Hungary. This prompted Mehmet II to launch a simultaneous assault against the land and sea walls in the early hours of the morning of Tuesday 29 May.14 The Byzantine emperor had concentrated his troops between the inner and middle walls, and when they were in position the gates of the inner wall were closed. There was to be no retreat. The Ottoman irregulars went in first but were driven back, as were the Anatolian infantry who followed them.

A final attack by the janissaries too...