 Hereswith's sister was Saint Hilda (or Hild), founder of the monastery at Whitby.Details of her life and identity come from Bede's "Historia Ecclesiastica", the "Anglian collection" and the "Lives" of Edwin of Northumbria and Hilda of Whitby.The Northumbrian royal descent of Hereswith is traced from Edwin of Northumbria (who ruled from about 616 to 632), the son of Ælle, King of the Northumbrian kingdom of Deira.