Dervan or Derwan (Serbian Cyrillic: Дерван, Latin: Dervanus) was an early ruler of the Sorbs (fl.
Fredegar records him being subordinate to the Franks for a long time and then joining the Slavic union of Samo.
Further reports of Fredegar imply that Dervan and his people lived to the east of the Saxon Saale.
The reference to Dervan in 631/632 is also the first written confirmation of the presence of Slavs north of the Ore Mountains.
[4][5][6] According to Tibor Živković, the migration of the Serbs to the Balkans could take place between 629 and 632, before Dervan joined Samo,[7] while according to Francis Dvornik it was during or after the Serbian state was weakened because of the war with Franks.