Peter Rex, in his 2005 biography of Hereward, points out that the campaigns in which he is reported to have fought in the region of Flanders seem to have begun around 1063 and suggests that, if he was 18 at the time of his exile, he was born in 1044/45.
Peter Rex, na súa biografía de Hereward de 2005, di que as campañas nas cales hai información de que loitó preto de Flandres comezarían arredor de 1063, e suxire que, se tivera 18 na época do seu exilio, nacería en 1044/5.