William Peverell (c. 1040 – c. 1115, Latinised to Gulielmus Piperellus), was a Norman knight granted lands in England following the Norman Conquest.
William Peverell the Elder was allegedly the illegitimate son of William the Conqueror by a Saxon princess named Maud Ingelrica (daughter of the noble Ingelric), although this cannot be supported by historical records. Maud Ingelrica was later married to Ranulph Peverell, from whom William took his surname. Beryl Platts suggested that the Peverel family in Normandy derive in fact from Flanders. Maud and Ranulph's known legitimate son, Ranulph Peverel, was almost as well favoured by the king as was his uterine brother William Peverel and was granted 64 manors in Nottingham, although these were forfeited by his family to King Henry II for their support of King Stephen against the Empress Matilda. The baronial family of Peverel descends from Ranulph Peverel, not from William Peverel.
There exist two possible etymological explanations of the surname Peverell. J.R. Planché sources it from the Latin puerulus, the diminutive form of puer (a boy), thus "a small boy", or from the Latin noun piper, meaning "pepper".
J.R. Planché derives the name as follows: "The name of Peverel ... was not derived from a fief or a locality ... the name was Peverell or Piperell, and in Domesday we find it continually spelt Piperellus (as in) Terra Ranulphi Pipperelli (i.e. "The lands of Ralph Pipperellus"). This, however, does not illustrate its derivation, and the detestable practice of Latinising proper names only tends to confuse and mislead us, as they become in turn translated or corrupted till the original is either lost or rendered hopelessly inexplicable. It may be that like Mesquin lesser, or junior, translated into Mischinus, and distorted into de Micenis, "Peverel" is the Norman form of Peuerellus, as we find it written in the Anglo-Norman Pipe and Plea Rolls. The "u" being pronounced "v" in Normandy, and Peuerellus being simply a misspelling of the Latin Puerulus, a boy or child, naturally applied to the son to distinguish him from his father. William Peverel was therefore, literally, "boy-" or "child-William". We see in the instance of the descendants of Richard d'Avranches how Mesquin, used to distinguish a younger son, became the name of a family, and so it may have been with Peverel, which, originally applied to William, was afterwards borne by so many of his relations in England."