The  Bavarian Geographer describes a multitude of people at that time. 

The Bavarian Geographer wrote the Descriptio civitatum et regionum ad septentrionalem plagam Danubii that means 'description of castles (fortified settlements) and territories (countries) north of the Danube river. In it he describes a large number of people not only north of the Danube rive, but at the Elbe to the Wolga river, between the Baltic Sea and the Black Sea to Caspian Sea and Caucasus mountain , from Khasaria to Finland.

Did Bavarian Geographer actually make a list, West Slavs, as Wikipedia implies?. How reliable is Wikipedia? Read Disclaimers.