The western and eastern borders (defined by language diffusion) of the medieval Germania Slavica are not identical to modern state borders. Due to the different accessibility to research bases, however, at the suggestion of Klaus Zernack, for pragmatic reasons, a distinction was made between Germania Slavica I and Germania Slavica Ii, separated by the Oder as a state border since 1945, although the historical landscapes of Pomerania and Lebus are intersected by the Oder. Germania Slavica 1 has recently been converted into a “northern” (Mecklenburg-Western Pomerania and Brandenburg ) and a "southern" ( Saxony ) divided.