Original sentence: A school of scholars maintains the theory of an Illyrian invasion, which involves a great movement of Illyrian tribes from the lowlands of central Europe (modern Hungary), towards South Eastern Europe and the Balkan peninsula.The Illyrian invasion is estimated to have occurred around the 13th century BC.The Illyrian invasion was most likely the key event which caused the Thracian expansion to the East, the movement of the Greeks to the south and the Phrygian migration from Thrace into central Asia Minor.The Illyrians were most likely in turn pushed Eastwards by other Celtic or Germanic from the North-West.The last even created the conditions for the Greeks to colonise the coast of Asia Minor and the Dorian Invasion.The numerous Thracian names in Illyria has lead many scholars to believe that the region was originally inhabited by Thracians, who were either deplaced or submitted to the Illyrian invaders
Edited sentence: However, this argument is very disputed.The Indo-European ancestors of the Illyrians (who have been dubbed the Proto-Illyrians) would have migrated into the Balkans in some undetermined early age, possibly shortly after the Eneolithic, which was the last phase of the Stone Age