 In the 7th century, the Avar Khaganate opened a door for Slavic demographic and linguistic expansion to Adriatic and Aegean regions.In the early 8th century, a new archaeological culture—the so-called "griffin and tendril" culture—appeared in the Carpathian basin.Some theories, including the "double conquest" theory of archaeologist Gyula László, attribute it to the arrival of new settlers, such as early Magyars, but this is still under debate.