The R1a-Y3300 (aka L1280) found in Serbia and Bosnia seems to have expanded from Poland via Hungary during the early medieval period. The Croatian R1a-Y2608 also expanded from Poland during the same period, but via Czechia, Slovakia, Austria and Slovenia.

Ez bizony a DAI jelezte szorb/fehér horvát vidékről történt beköltözés lehet, "Hérakleiosz császár idejében". (Egy kis avar hozzátéttel, akár.)