Research Notes:

Adam of Bremen names Olav as son of King Erik & his (unnamed) wife who later married Svend King of Denmark. Snorre names "Olaf the Swede" as the son of "the Swedish king, Eirik the Victorious" and his wife Sigrid. According to Saxo Grammaticus, after his father's death, he returned to Sweden [from Denmark] with "his mother Syritha, and stayed there exercising his sovereignty under his mother's tutelage".

He succeeded as OLOF I "Skotkonung/under-King" King of Sweden. Adam of Bremen records that King Olof invaded Denmark and expelled King Svend, but allowed him to return to his kingdom because "matrem suam habuerit". He converted to Christianity and was baptised as "JACOBUS". ¹