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.
It was while this contest was at its height that the new invaders attracted the attention of Arnulf; and, in the year 892, finding himself in a desperate plight, he persuaded the Hungarians to join him in an invasion of Moravia. Svatopluk fought gallantly against his enemies, and more than once repelled them from his dukedom; but, in 894, he was finally defeated by the combined forces of his opponents. Then comes in a story which illustrates in a startling manner the Bohemian feeling that no military successes could atone for acts of cruelty and treachery. Although Svatopluk was undoubtedly fighting for the independence of his country, he was seized, according to this legend, with so extreme a fit of penitence for his crimes, that he fled from the battle to a secret place in the mountains, where he killed his horse, buried his sword in the ground, and lived and died a hermit. What gives a still stranger flavour to the legend is the cause which Cosmas assigns for the Duke’s penitence; for this cause was not his persecution of Methodius, but his ingratitude to Arnulf.