However, there are three major problems in studying the spread of early Slavic groups by purely archaeological methods.
Consequently, discerning where in northern Europe Slavic groups lived during the 6th to 9th centuries represents a challenge.
The alphabet depends on what religion is usual for the respective Slavic ethnic groups.
Their dialect is transitional between west and east South Slavic group.
Sorbs, an West Slavic ethnic group in the eastern Germany.
Slavic groups in the area were in constant war with Byzantium and tended to establish a new state.
This is particularly true of Slavic cultural groups.
It is the group with the largest numbers of speakers, far out-numbering the Western and Southern Slavic groups.
As explained above, the Slavic groups have been declining ever since the 1960s, due to low birth rates and high death rates.
Even so, other Slavic groups also had demons of bad weather.