From The Making of Eastern Europe: From Prehistory to Postcommunism, by Philip Longworth (Lume Books, 2020), Kindle pp. 367-370). Lume Books. Kindle Edition.
Population pressure seems to have been the primary cause of the Slav’s expansion; but, unlike most other barbarian groups who moved in large, warlike, parties, the Slavs seem to have extended their areas of settlement gradually, seeping into more and more territory, moving in little groups along the waterways of Eastern Europe, building small, unfortified villages on river banks, and, when need arose, moving into the forests, slashing, burning and growing grain in the resultant clearings. The idea that the Slavs were peaceful, however, is mythical: they wielded a variety of weapons and were adept at ambush and the use of poisoned arrows. But they mingled with, as well as fought, other peoples, and were sometimes dominated by them. They constituted a significant portion of the subject population of Atilla [sic] the Hun, for example, as they did of the Bulgars.
The Bulgars were Turkic-speaking pastoralists who crossed the lower Danube into Byzantine territory at the end of the fifth century. By the middle of the sixth they had become a menace to Byzantine order in the Balkans and more than once threatened Byzantium itself. To a Byzantine chronicler it seemed that ‘these barbarians, having once tasted the wealth of the Romans, never forgot the road that led to it’.
The Bulgars were soon displaced as the major threat by a people called Avars, who had been driven out of Central Asia to the northern Caucasus. In 557 they proposed an alliance with Byzantium. By 570 they dominated central Europe. The fact that a particular tribal grouping occupied an area, of course, does not imply that its former inhabitants had disappeared. In fact the Avars, like the Bulgars, had, as one scholar expresses it, turned from herding animals to herding men. In doing so they had to ensure that their slaves had sufficient to live on. Such may have been the purpose of the Avars in overrunning Greece together with the Slavs in the 580s. At least, many Slavs remained after the Avars withdrew. It should be noted that the dominant group in any tribal mingling did not necessarily impose its language and customs on those they ruled. It was often the conqueror that was absorbed linguistically by the conquered. The language of the Bulgars, for example, became primarily Slavonic rather than Turkic; and the Slavs in Greece adapted themselves not only to mountains and to an economy dominated by the olive and the vine, but to the Greek language and the Christian religion. On the other hand Greek nationalists who to this day insist that the modern Greeks are the genetic descendents of the ancient Greeks, uncontaminated by Slav blood, conveniently overlook the predominance of Slavonic place names in parts of the Pelepponese [sic].
The spurious association of language, territory and genetic inheritance became a particular curse of the region in the nineteenth century (see Chapter 5), and a study of the early mediaeval period reveals many modern nationalist claims to be romantic invention and embroidery. The nationalities of the modern age were to emerge out of a swirl of dialects and cultures. The ancient Greeks and Romans, like the Thracians and Dacians, left their marks. They are to be found, along with the Illyrian legacy, in modern Albanian.
At the same time Romanian (for all the work of ‘purification’ done on it in the nineteenth century) reveals strong traces of Illyrian, Bulgar, and Slavonic as well as Latin. And Dacians, Romans, Gepids, Goths, Bulgars, and Slavs, among others, contributed to the genetic inheritance of the Romanians, as they did in varying proportions to those of other modern nations of the Balkans. At the same time languages, like peoples, changed and even disappeared. The Russian Primary Chronicle, composed centuries later, was essentially correct in stating that Slavonic was a single language, and that Slavonic and Russian were the same; and this was certainly no less true in the time of the great migrations than it was around 1100 when the Chronicle was composed. In the course of time, however, contacts with different peoples and adaptations to different ways of life in different geographical environments promoted linguistic changes. The West Slavs, including proto-Czechs and proto-Poles, were gradually to draw apart from the East Slavs; and the south Slavs from the others. The arrival in the later ninth century of the Hungarians, who spoke a quite different language, was to accelerate the process because they interposed themselves as a linguistic barrier between the South Slavs and the rest. However, even before this the Slavs did not constitute a homogenous mass geographically. Other linguistic groups, Lithuanians, Prussians and proto-Romanians, constituted barriers of sorts as did the topography of the region: the mountains, the marsh-lands and the forests.
Later still, differentiations were to occur within each major grouping of Slavs so that Ukrainian, under Polish and Romanian influences, drew apart from Russian, and Serbian from Slovene. At the same time the Slavs in Greece were not the only ones to be assimilated, and no doubt distinctive Slavonic dialects, if not languages, disappeared along with them. It was the extinction in the mid-eighteenth century of Polabian, which had been spoken in an area west of the River Elbe in Germany, and the decline of the Sorbian-speaking communities on the banks of the River Spree that was to move Herder so deeply. But for all the differences between them the Slavonic languages which survived remained closely related. Even today Russians do not find great difficulty in understanding Bulgarians or Slovaks, and there are Macedonians and Croats who will admit that speaking to each other is akin to using a different dialect rather than a different language. In the seventh century, as indeed in the ninth, we may be certain that all Slavs could understand each other.
Far Outliers 