Complex sentence: The Daesitiates were unquestionably one of the main components of the Illyrian ethnical complex that stretched from the Southern Adriatic to the Danube in the North, and they lived in the centre of the Illyrian West-Balkan and Pannonian world.
Split into simpler sentences: The Daesitiates were unquestionably one of the main components of the Illyrian ethno-cultural complex that stretched from the southern Adriatic to the Danube in the north. They specifically lived in the centre of the Illyrian West-Balkan and Pannonian world.