Perhaps few families in England can shew a fairer pedigree than is here disclosed, for that portion of it, always the most difficult to prove, which covers the troubled tenure of the House of Plantagenet is singularly clear and distinct, and from the time of the first Plantagenet there is no manner of doubt concerning its accuracy; and it is also equally clear that the Glanvilles were settled in Suffolk, if not as chief tenants, yet as great Lords, in the time of Domesday - the first pages of this book exemplify that fact beyond any doubt; but the history of the family, as contained in these Records, from the date of Domesday to that of Ranulf de Glanville, the great Lord Chief Justice of England, who was unquestionably one of the greatest men of his time, is not quite so satisfactory.

Credit: See http://www.glanvillenet.info/roanhg1.htm 

Henry II of course is one of the most well documented genealogies and histories of all time.