The Avars, as shown on the map, played a big role in the medieval South-Eastern Europe. Around year 600, the are of influence was as biggest. Originally there’s no information of their language, or ethnolinguistical affiliation. Much later they shifted to start speaking [Proto-]Slavic language.
I was cleaning my old PC from files that I downloaded years ago.
Guess what I found? Well, old files from The Indo-European Database website. I kept spending time on this site in the beginning of this millennium. The site that focused on Indo-European languages featured language overviews, linguistic maps, and much more.