 There is uncertainty of both the date and the place of Olaf's birth.The earliest Norwegian written source, the "Historia Norwegiæ" of the late twelfth century, states that Olaf was born in the Orkney Islands after his mother fled there to escape the killers of Olaf's father.Another late 12th-century source, "Ágrip af Nóregskonungasögum", states that Olaf's mother fled to Orkney with Olaf when he was three years old for the same reason.