Scholars have hypothesized the name Croat (Hrvat) to be Iranian, thus suggesting that the Croats were actually a Sarmatian tribe from the Pontic region who were part of a larger movement of Slavs toward the Adriatic.
Another theory is that the name comes from Old Church Slavonic Churvatinu "Croat," literally "mountaineer, highlander," from churva "mountain" which also has its cognate in the Russian word khrebet "mountain chain") [REF].