Oswine was of the royal house of Kent. Gordon Ward, writing in Archaeologia Cantiana suggests that Oswine was a grandson of Eormenred of Kent, possibly the son of Æthelred of East Kent.
Oswine was a member of the royal family of Kent, as suggested by Gordon Ward in Archaeologia Cantiana, potentially being the grandson of Eormenred of Kent and possibly the son of Æthelred of East Kent.