"What an exciting new place to adventure in!" - Nomads about to reshape continental politics

Explanation: In the 9th and 10th century AD, a tribal confederation of nomads steadily migrated into what-we-now-call-Hungary. After a few hundred years of migrating steadily westwards, bit by bit, they found their way to Central Europe. After some time spent familiarizing themselves with the region, the Carpathian Basin was suitable enough to their tastes and way of life that it would become their permanent home. How exciting, to take the first steps into this new land!

… the rest of Europe was less enthused by the new invader/migrants, especially as the Hungarians did not initially share their religion (Christianity), and Christian polities made several (failed) attempts to drive them out. Even after the Hungarians converted, anti-Hungarian sentiment was not uncommon in Central Europe, denigrating the Hungarians as in some way savage or monstrous. God preserve us!