the failure to organise south-eastern Europe was to have disastrous results. The restored Byzantine Empire succeeded in regaining part of Asia Minor, now that Europe was lost to it. But in 1329 the sultan of the Ottoman Turks who from being subjects of the Seljuks now formed an independent power, drove it back to the capital and its environs. From enemies they became allies, and were more dangerous in the latter capacity than the former. Called in to aid the Empire against the Serb, they did their work only too well. The advance of the infidel into Christian Europe created a sensation even in the remoter West, and provoked a temporary unity in the East. The Magyars came to the aid of the Serbs to meet defeat. In 1389, Sultan Murad, who was killed in the battle, ended Serbian independence at Kossovo. The Turks were now on the Danube, and Sigismund, a belated crusader, came to the aid of the threatened Hungarians at the head of a motley crew of knights and nobles, some of them from distant France, only to be disastrously defeated at Nicopolis (1396).
The Turk was now master of the Balkans; it only remained for him to end the Eastern Empire. The advent of Timur the Tartar momentarily wrecked the Turkish Empire, or at least its base in Asia, but the scourge soon passed. In 1422 a great attack on Constantinople failed, but the Greeks were now driven into their last stronghold. An appeal was made to a common Christianity for aid. The Pope, indeed, used emergency as opportunity and secured theological unity and recognition of Papal supremacy, but the Constanti-nopolitans would have none of it; they preferred the unbeliever to the Latin. No aid came from Rome or the West. The only aid to be expected was from individuals and from the nation which would next be exposed to invasion. John Hunyadi, a Transylvanian nobleman at the head of a host of eastern crusaders, was the onlythough no smallobstacle to Turkish progress. He won a brilliant victory in Serbia in 1443, but he could never persuade quarrelling kings and princes to give him that support which would have enabled him to follow up his victory. He did indeed induce the Polish king Vladislas VI. who was also, by reversion to the old game of the dynasts, King of Hungary, to lead an official Magyar host, but only to his death at Varna. In the general disarray, the Turkish wave surged forward again. In 1448 Hunyadi's last effort decisively failed at the second battle of Kossovo after three days' furious fighting, a result mainly due to the Serbs who fought for the Crescent as Turkish vassals.
There was now no hope for the Eastern Empire save in the thickness of the walls of Constantine's city. A lost outpost of Christendom, it died worthy of its founder after a long and magnificently obstinate defence; the last of the Caesars, himself a Constantine, met a hero's death on the breached walls (1453). Except in the hearts of its followers the Greek Church was now without power; generations were to pass before it was once again to be the national religion of a great state. The result of the fall was the exodus of those scholars who brought the manuscripts of ancient Greek literature to be printed in the West in the age that succeeded Petrarch and Boccaccio, the pioneer figures of the cultural Renaissance. The new age was culturally and intellectually to be built not merely in the classical tradition but on the classics themselves.