Osferth or Osferd or Osfrith, was described by Alfred the Great in his will as a "kinsman", he may have been a relative of Alfred's mother Osburh, or Osburga was the first wife of King Æthelwulf of which location?
Osferth:  Simon Keynes and Michael Lapidge suggest that he may have been a relative of Alfred's mother Osburh, or a son of Oswald "filius regis" (king's son), who may in turn have been a son of Alfred's elder brother and predecessor as king, Æthelred I.
i don't know