the "Sclaveni" and then to the Gepids, "taking with him not only those of the Longobards who had followed him, but also many of the Sclaveni" in the 540s. According to a scholarly theory, Hildigis most probably mustered his Slavic warriors in the region of the Middle Danube. The Germanic Longobards were expanding towards the Middle Danube in the early . Archaeological research shows that Longobard expansion bypassed virtually the entire territory of Slovakia and they settled only in the most north-western part of the country (Záhorie). Unlike neighbouring Moravia, Slovakia (except of Záhorie) did not belong to any German empire in this time. The Longobards and the local Slavs remained separated by the natural border formed by Little and White Carpathians, respected by both sides according to Ján Steinhübel. He also writes that the Slavs, who remained "an independent third party" in strained Longobard-Gepid relations, were not interested in conflicts with their Germanic neighbours, but made raids in the faraway Byzantine Empire. Avar Khaganate The Longobards left the Carpathian Basin for Northern Italy after the invasion of the territory by the Avars in 568. The Avars were a group of nomadic warriors of mixed origin. They conquered the Carpathian Basin, subjugated the local peoples and launched plundering expeditions against the neighboring powers during the next decades. By the time of the Avars' arrival, the Slavs had settled in most lands that now form Slovakia, according to historian Stanislav Kirschbaum. Further migration waves strengthened the local Slavic population because new Slavic groups, pressed by the Avars, crossed the Eastern Carpathians, seceding from the Slavs who continued their expansion to the Balkan Peninsula. Dialects of Slovak still reflect that the Slavs came from different directions already in the Early Middle Ages, according to a widely accepted scholarly theory. Czech and Slovak share some features with the South Slavic languages, distinguishing them from the other West Slavic languages. According to archaeologist P. M. Barford, these features suggest that the Carpathian Mountains and the Sudetes separated the ancestors of the Slovaks and the Czechs from the Slavs living to the north of those mountains. Especially the dialects of Central Slovakia, which "stand out from the continuous chain between the western and eastern dialects", preserved South Slavic features. The 7th-century Frankish Chronicle of Fredegar wrote that the Avars employed the Slavs, or Wends, as "Befulci", showing that the Slavs formed special military units in