In addition, there may be some partisan bias in the early writers: the notice of Hereward in the Peterborough Chronicle, for instance, was written in a monastery which he was said to have sacked, some fifty years after the date of the raid.
Ademais, pode haber algunha toma de partido nos escritores antigos: os datos sobre Hereward na Crónica de Peterborough, por caso, foron escritos nun mosteiro do que se di que él o saqueou, uns cincuenta anos após a data do asalto.