Composed around the year 600, the east Roman military treatise often attributed to the Emperor Maurice (582-602) includes a fascinating comment on the approach of some early Slavic groups to prisoners taken on their raids:

They do not keep those who are in captivity among them in perpetual slavery, as do other nations. But they set a definite period of time for them, and then give them the choice either, if they so desire, to return to their own homes with a small recompense, or to remain there as free men and friends.[1]

This undoubtedly raises the basic intellectual problem involved in trying to understand the astonishing rise to prominence of Slavic speakers all the way from the Elbe to the Volga in the early Middle Ages. On the one hand, there is no-one who supposes that this could have happened without an element of migration: actual Slavic speakers on the move across the landscape. On the other, old culture-historical, quasi-nationalist visions of the Slavs as a “people,” a single population group that started from one geographical point and then went forth to multiply over vast tracts of the European landscape, are not credible.

From Peter Heather’s Empires and Barbarians: Migration, Development, and the Birth of Europe, London: Pan Books, 2009, p. 428.

Footnote

1. Maurice, Strategicon, 11.4.