The end of resistance to the Ottomans in Albania, northern Serbia and Bulgaria was to provoke energetic, though belated, action in the west. The Turks were in fact halted by Mongol armies from the east, not by the Christians from the west, but the ‘Crusade of Nicopolis’ of 1396 is an event of sufficient significance to justify a brief excursus on the history of crusading thought in the century after the disappearance of Christian rule in Syria. Throughout this period there was much discussion concerning the methods to be used to regain the territory now lost to Christianity. The ideas of the Catalan Ramon Llull (1232–1315/16) are of interest for their originality, though they had no practical effect. Llull had plans for military reconquest, but his most novel recommendation proposed the foundation of chairs of oriental languages in western universities. Muslims were to be converted by what might now be called ‘brain-washing’. Special linguist-preachers should ‘hold disputations with prisoners to convert them to the Holy Catholic faith’, and they should read certain books which prove that Mahomet was not a true prophet.
Afterwards the ruler-commander [under whom the military religious orders were to be unified] should release these captives. He should pay them their travelling expenses with a fair and friendly expression on his face, and send them off to the Saracen kings and other rulers … so that they should make clear to them (the rulers) what we believe concerning the most holy Trinity … and this will be a way of converting the Infidels and of spreading our most holy faith.
The most fundamental of the many disadvantages of this scheme was that the Christians very rarely succeeded in taking Muslim prisoners.
In the early fourteenth century the Byzantines lost western Anatolia to the Turks, of whom the most successful were the Ottomans who established themselves opposite Constantinople. This blocked further expansion until 1354, when involvement in the Byzantine civil wars allowed the Ottomans to establish a bridgehead at Gallipoli. This became their base for the conquest and settlement of Thrace, completed with their victory in 1371 over the Serbs at the battle of the Maritsa. Turkish expansion has been attributed to the ghazi-ethos, i.e. the Turks were warriors for the faith bent on extending the frontiers of Islam. They were also pastoralists seeking new lands for their flocks. They fed on the weakness of their opponents. In 1387 Thessalonica, the second city of the Byzantine Empire, voluntarily submitted to the Ottomans. In 1389 the Serbs were defeated at Kossovo and became their tributaries. In 1393 the Ottomans entered Trnovo and annexed Bulgaria. They were also taking over the Turkish emirates in Anatolia, including in 1397 Karaman.
The threat from the Turks gave a new lease of life to the crusade which had lost its purpose after the fall of Acre in 1291. The Knights Hospitallers led the way. In 1308 they seized Rhodes from the Byzantines and used it as a base against Turkish piracy in the Aegean. Their success encouraged crusading activity which suited Venetian commercial interest and pandered to nostalgia for the glories of the crusade. There was a fashion for the creation of chivalric orders dedicated to the promotion of the crusade. The main success came with the crusade of 1344, which conquered Smyrna, handing it over to the Knights Hospitallers. The initiative thus wrested from the Turks in the Aegean, the focus of the crusade now became Cyprus, where Peter I was preparing a crusade against the Mamluks of Egypt. Alexandria was stormed in 1365, but any further progress was dampened by the Venetians who feared for their trade with Egypt.
During the period of internal wars in Hungary, relations between the kingdom and its neighbours changed profoundly and irreversibly. Ottoman expansion reached Hungary in 1389 and the kingdom was soon compelled to adopt a defensive policy to counter this threat. From this time until the catastrophe of Mohács, Hungary lived, almost without interruption, under the constant menace of Ottoman raids and invasions, which, besides straining her economic and military forces to the limit, also led to internal conflicts. Proud of their ancestors’ warlike traditions, the nobility found the necessity of a defensive policy unacceptable. They demanded the same offensive attitude towards the Ottoman empire as had for so long prevailed towards others. The failures that were bound to follow were invariably blamed on those who happened to be in power.
In early 1389, Lazarus, prince of Serbia, confirmed his allegiance to Sigismund, but he was killed in June at the battle of Kosovo, and his son Stephen Lazarević soon became an Ottoman vassal. In early 1390 Turkish troops devastated the region of Timişoara, in 1391 they did the same in Srem, and thereafter their incursions became regular occurrences. Sigismund took the threat seriously from the very first moment. As early as the autumn of 1389 he led an expedition to Serbia, taking Čestin and Borač by siege, and he repeated the action in 1390 and 1391. In 1392 he pushed forward as far as Ždrelo, but Sultan Bayezid, who arrived there in person, refused to give battle. In 1393 the barons led a campaign along the southern frontiers, and Sigismund was also there in August 1394. In early 1395 he mounted an expedition against Moldavia and forced its prince to submit, but this success proved only temporary and Moldavia soon shifted back under the influence of Poland. By this time Wallachia had passed temporarily under the suzerainty of the Ottomans, who raided Transylvania for the first time in 1394. Mircea cel Bătrîn, prince of Wallachia, who had hitherto opposed Hungary with Polish support, asked Sigismund for help in order to regain his land. On 7 March 1395, in Braşov, he agreed to be a vassal of Hungary. However, on 17 May the Hungarian army sent to Wallachia was defeated and its commander, Stephen Losonci, killed. In July Sigismund himself invaded the province, restored Mircea to his throne and recovered from the Ottomans the castle of Minor Nicopolis on the Danube.
These wars were exhausting and yielded only meagre results. Consequently, Sigismund decided to settle the Turkish problem once and for all. He set about organising a major enterprise with the ambitious aim of driving the Ottomans out of Europe. In 1395 his envoys made a tour of the courts of Europe and an embassy may also have been sent to the Mamluk sultan of Egypt. As a result of these efforts the Pope declared the planned expedition a crusade, and by the summer of 1396 an army of considerable size had assembled. Alongside the Hungarians and their Wallachian auxiliaries, the core of the army was made up of Frenchmen, with John of Nevers, heir to Burgundy, at their head, though knights also came from Germany, Bohemia, Italy and even England. In August the army, led by Sigismund, invaded Bulgaria along the Danube and laid siege to Nicopolis. Bayezid, leading the counter-attack in person, marched to relieve the beleaguered castle, and it was there that a European army faced the Ottomans for the first time. The battle, which for a long time was to determine the nature of Hungaro-Ottoman relations, took place on 25 September 1396. The crusader army was virtually destroyed, allegedly as a consequence of the ill-considered actions of the French knights. As for Hungarian casualties, several barons were killed, Palatine Jolsvai captured, and Sigismund himself barely escaped with his life, fleeing on a ship to Constantinople and returning by sea to Dalmatia in January 1397.
The last of the major crusading ventures was the outcome of the great Ottoman victory of 1389. Like the al-Mahdiya expedition, the Crusade of Nicopolis was made possible by the long lull in the Anglo-French war. In 1395 negotiations led to the formation of a league involving France, England, Hungary, Venice and Burgundy: Duke Philip the Bold was the principal promoter and his son John of Nevers (the future John the Fearless) commanded the Franco-Burgundian element. More than half of the very large Christian force involved were Hungarians. In the summer of 1396 this army advanced from Buda along the Danube and besieged Nicopolis. Sigismund of Hungary, experienced in warfare against the Ottomans, favoured cautious tactics, but the French could only think in terms of the headlong chivalric assault which had cost them so dear at Crécy and Poitiers. When Bayezid broke off the siege of Constantinople and came to the aid of Nicopolis the French at once launched an attack (25 September 1396). After winning ground in the early stages of the engagement, they were defeated with the loss of almost their entire force. The Ottomans then turned against the Hungarians, who had held aloof from the French battle, and they too were overcome. Most of the French prisoners were put to death, but Bayezid spared the nobles, who were later ransomed for a fee of 200,000 florins. Among these was John of Nevers, who reached home the following year.
The catastrophe of Nicopolis demonstrated that the Ottoman empire represented a power against which Hungary was unable to wage an offensive war, even with support from abroad. The hope that Ottoman attacks might be stopped through a single determined effort vanished. From this point on priority was given to defence rather than to offensive campaigns. The kingdom had to learn how to live with the constant menace of Turkish incursions.
The great military undertaking of 1396 had failed to halt the Turkish advance and Constantinople would almost certainly have fallen within a few years but for the defeat of Bayezid by Timur in 1402. Throughout the preceding century the western Christians had compared unfavourably with their opponents—whom they had consistently underrated—in every respect. Their tactics and discipline had been inferior and they had fought in unsuitable armour. Above all, their efforts had been spasmodic and had been frustrated by internal divisions and conflicting motives. As an old man, Philip of Mézières, the great crusading propagandist of the age, learned the news of the crushing defeat of his hopes at Nicopolis. In these last, sad years of his life he was accustomed to write of himself ruefully as a vieil abortif‘(an old failure).
Bayezid’s defeat and capture near Ankara in 1402 postponed Ottoman domination throughout south-eastern Europe for several decades. During this period both Venice and the kingdom of Hungary were sufficiently powerful to dispute what was left of the Eastern Empire with the Turks—though inevitably they were rivals and not allies. After the death of Sigismund (1437) Hungary lost much of its cohesion, and the eventual successor, Ladislas of Poland, had to struggle for control in Hungary as well as fighting the Turks in Serbia. The campaigns of 1442–4, which probably saved Constantinople from conquest by Murad II, were fought under the virtual leadership of John Hunyadi of Transylvania, a Wallachian noble who had come into prominence in the service of Hungary. Hunyadi was also involved in the attempt to exploit Murad’s absence in Asia during 1444, which culminated in the disastrous defeat of Varna, in which king Ladislas was killed. Surviving this battle, Hunyadi became regent in Hungary for Ladislas Posthumus, the grandson of Sigismund and heir to Ladislas III. Hunyadi in his turn became preoccupied with internal factional strife, and in the following years the main role in opposing the Ottomans was assumed by the Albanian George Castriot, later known as Scanderbeg (born c. 1405). Scanderbeg had been taken by the Turks in youth as a hostage and, as a Moslem, served them for many years before he fled to his native land and set up as the leader of resistance there in 1443.