The
Anthrogenica member who made the
genetic distance maps showing that Ancient Greeks and Romans were identical to Modern Italians did the same thing with Iron Age (pre-Slavic) Balkan samples, confirming that they were also genetically similar, with "Croatians" in the north being more Northern Italian-like and "Bulgarians" in the south being more Southern Italian (and Greek)-like.
This is indigenous Southeastern European ancestry combining Neolithic Farmers and Bronze Age
Indo-Europeans, which is clearly
the same ancestry that's still in Italy today.
Iron Age Croatia:
Iron Age Bulgaria: