Breaking out occasionally into armed conflicts, and among the princes of the other principalities the old struggle for precedence and territory went on unceasingly until it was suddenly interrupted, in the first half of the thirteenth century, by the unexpected irruption of an irresistible foreign foe coming from the mysterious.
The beginning of his reign was marked by a disastrous irruption of the Hungarians into Burgundy and Aquitaine (937).
The wild animals of Caucasia are for the most part the same as those which frequent the mountainous parts of central Europe, though there is also an irruption of Asiatic forms, e.g.
So important was this traffic held at Constantinople that, when the portage to the Don was endangered by the irruption of a fresh horde of Turks (the Petchenegs), the emperor Theophilus himself despatched the materials and the workmen to build for the Khazars a fortress impregnable to their forays (834).
This result he achieved in spite of the Decian persecution (250251), during which he had felt it to be his duty to absent himself from his diocese, and notwithstanding the demoralizing effects of an irruption of barbarians (Goths and Boranians) who laid waste the diocese in A.D.