Clarence Ellis in `Hubert de Burgh A Study in Constancy' looks at the evidence for the parentage of Hubert de Burgh. Possibly the best piece of evidence (and virtually the only piece) for the identity of his father is the mention in the Pipe Rolls of the debt being repaid by Adelina daughter of Walter de Burgh, this Walter must have been dead by 1179-80, see Ellis pp 191-92.
Stephen