TheHevelli orHevellians/ Navellasîni (sometimesHavolane;German:Heveller orStodoranen;Polish:Hawelanie orStodoranie;Czech:Havolané orStodorané) were a tribe of thePolabian Slavs, who settled around the middleHavel river in the present-dayHavelland region ofBrandenburg in easternGermany from the 8th century onwards.
West Slavic tribes ("Wends") had settled in theGermania Slavica region from the 7th century onwards. TheHehfeldi as they were called by theBavarian Geographer about 850 built their main fortification at Brenna (later to becomeBrandenburg an der Havel) and a large eastern outpost at the current site ofSpandau. In 906 the Hevelli princessDrahomíra married thePřemyslid dukeVratislaus I of Bohemia.Baçlabič was the prince of Hevelli from 921-936, succeeded byTugumir.[1]
Brenna was occupied by theGerman kingHenry the Fowler in his 928/29 Slavic campaign and incorporated into theMarca Geronis. Henry's successorOtto I in 948 established theBishopric of Brandenburg in order to Christianize the pagan population. These efforts were aborted in the course of the 983Great Slav Rising in theNorthern March, which again defied German control over the region. Together with the neighbouringSprevane in the east, the Hevelli waged war against not only the GermanSaxon forces to the west, but also other Slavic tribes.
The baptized Hevelli princePribislav (died 1150) finally bequested his lands to theAscanian countAlbert the Bear. Albert until 1157 could re-conquer the territory of the former Northern March, whereafter he established theMargraviate of Brandenburg. The Slavic Hevelli were gradually assimilated byGerman settlers in the course of theOstsiedlung.