Well, Barbarians -> Bulgarians. We can conclude that everything to the north of Ancient Greece (an odd island or two) was pretty much all Bulgarian.
P.S: Likewise you may have heard of Conan the Barbarian, whose name is probably a corruption of Nikola. He was allegedly from Cimmeria, which is exactly where Old Greater Bulgaria was situatied. In the interest of historical accuracy he should be renamed to “Nikola the Bulgarian”.