Under his rule Moravia had become the centre of a great Slavonic alliance extending eastwards to Bulgaria and northwards to Magdeburg. The exact relations between the dukedom of Moravia and the other States referred to may be difficult to define; but the whole story of his relations with Bohemia shows that Svatopluk exercised an authority there which was, at least, equal to that maintained by the German Emperor over many of the states subject to him; and we may fairly assume that he held a somewhat similar position towards the other Slavonic States which surrounded him. Such a position, in the then condition of Europe, could not but excite rivalry and jealousy among the neighbouring princes; and Arnulf, the Duke of Pannonia, who had aspired to the throne of the Frankish Empire, was particularly jealous of a man whose power, as he considered, had been largely due to the patronage which Arnulf had granted to him. The exact merits of the numerous quarrels between these princes it is impossible to estimate accurately; but it is clear that, as Svatopluk gained power, he became more and more resolved to throw off the authority which Arnulf found difficult to assert. At last Arnulf, having lost hope of maintaining his authority by his own force, and perhaps suspecting that Pannonia would itself fall a prey to his rival, resolved to call in a new ally to his assistance. The emperors of Constantinople had followed the tradition of the Western Empire, by playing off their barbarian invaders against one another. And, as the Romans had used their alliance with the Goths to drive back the hordes of Attila, so the Emperor of Constantinople had called on the descendants of Attila’s followers to protect the decaying empire from the inroads of the Bulgarians. It was apparently in the latter part of the sixth century that the Hungarians, or, as some called them, the Turks, had been driven into Europe by the pressure of other Asiatic races. They had been hospitably received at Constantinople, and, after various fortunes, had settled, in the eighth century, among the Chazars. But they were never allowed to remain long in one place; and it was in consequence of their alliance with the Emperors of the East that they overran Transylvania, and secured their first settlement in their future kingdom. Even here, however, they were not allowed to remain quietly, and another tribe succeeded in driving them out of Transylvania for a time.