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. Constantinople only survived because of Tamerlane who invaded Anatolia and in 1402 defeated the Ottomans at Ankara. They needed nearly twenty years to recover from this defeat, but under Murad II (1421-51) almost all the losses in the Balkans and in Anatolia, Karaman excepted, were made good. Murad also put Ottoman power on a sounder basis by regulating recruitment into the janissaries, the slave troops who formed the core of the Ottoman army. It was left to his son Mehmed the Conqueror (1451-81) to take Constantinople in 1453, thus endowing the Ottomans with a worthy capital, capable of holding their territories together and of enhancing the authority of the sultan. Mehmed rounded off his territories by annexing the remnants of the Byzantine Empire in the Peloponnese (1460), Trebizond (1461) and , the Karaman (1468). Already a major power, the Ottomans were poised for the mastery of the Mediterranean.
The threat from the Turks gave a new lease of the 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.
The Ottoman advance into the Balkans shifted crusading interest to Byzantium. In 1366 Amadaeus of Savoy went to the rescue of his cousin, the Emperor John V Palaiologos. The survival of Constantinople was a matter of urgency for the Hungarian King Sigismund, if only to divert the Ottomans from his frontiers. He was able to tap the crusading idealism of the French courts, already exploited in 1390 by the Genoise with Louis of Bourbon's crusade against Tunis. The new crusade was led by John the Fearless, the son and heir of the duke of Burgundy. The French met the Ottomans at Nicopolis in 1396 and were hopelessly defeated. This disaster effectively ended French participation in the crusade, although the Burgundian court continued to pay enthusiastic lip-service to the ideal. The crusade against the Ottomans became very much a Hungarian preserve. It came to grief in 1444 at Varna where a Hungarian crusade marching to the relief of Constantinople was defeated in a desperate two-day battle. Thereafter the crusade was relegated to the realms of wishful thinking. The Ottomans had proved too strong.
A friend had recently asked many questions about Turkey and Tatars and Greek history. The history of Turkey is rather complex, with many layers of history, conquest, empire, and tides of religion and power. I didn't have many of the answers to his questions.
I told him Tatars are Turkic and not Turkish.
That was a start.
He asked why all the best Greek ruins are in Turkey. He asked many questions about Turkey's concept of its place in the modern world. Most Americans ask about the film "Midnight Express".