Drevani  known as the Draväno-polaben or Drevanen  - Polabian Slavs
See also Polabia

Formed from:
Now the grounds where they lived are named Lüneburger Heide or Wendland and situated south of Hamburg.
The language became extinct on 19th century.

Cities or towns:
Iskorostan, Rerik,

Neighbors
10th Century:
Ottonian Empire to the W., Pomerania & Poland to East, Bohemia to S.

Sources for Research:
The Early Slavs P.M. Barford

Vernadsky’s works Kievan Rus

Interesting Links:

History & map and tribes:
       http://en.wikipedia.org/wiki/Polabian_Slavs