Some scholars consider that Albanians are direct descendants of an Illyrian tribe that was named "Albanoi," which was located in modern-day Albania. Others scholars dispute this, while others claim that Albanians and Illyrians are descendants of the ancient Pelasgians, making their history go back at least 4,000 years BCE. Others claime that Albanian derives from a dialect of the now-extinct Thracian language and that the Albanians are not autochthonous. Some others believes the majority of the Illyrians were conquered and/ or assimilated by the invading Slavic tribes after the fall of the Roman Empire. The perception of Illyrian as centum language was based on analysis of Venetic language in northern Italy which scholars believed was related to Illyrian language. Recent research show that this language and Illyrian had nothing in common and that Illyrian probably was Satem language after all.
Those who support the Illyrian-Albanian continuity theory maintain that all Illyrian tribes, except the Albanians, were assimilated or driven southwards into Albania and Greece during the Early Middle Ages after the waves of migrating barbarians. A formidable mountain homeland and resilient tribal society enabled the Albanians to survive into modern times with their identity and their Indo-European language intact. According to these scholars, the name 'Albania' is derived from the name of an Illyrian tribe called the Arbër, or Arbëreshë, and later Albanoi, that lived near Durrës.