It saddens me to read that the old slander that William The Conqueror's mother was the daughter of a tanner. That particular pice of mischief is a classic example of Dr. Goebbel's aphorism 'that if you repeat a lie often enough, it will be believed.' That inaccurate story originates in the Saxon Chronicles where it was used prior to the conquest to denigrate William and devalue his claim to the English Crown. Sadly it has ben repeated ad-infinitum, most recently by Simon Schama. The truth is somewhat different.
William the Conqueror’s mother was 'A Tanners daughter of Falaise' according to all who quote the Saxon Chronicles which were written in an attempt at propaganda to denigrate William. In fact his mother was Hereleve, the daughter of Fulbert a burgess who was also a household official in the Court of Normandy with the title 'Cubicularis' and, as such, a person of consequence, 'petit noblesse' ranked just belwo knightly rank (cited by McLynn F (1998) in '1066, a year of Three Battles' - p. 23) Willima's uncles, Herleve's brothers, apear as testators for the infant William. The Count of Flanders (whose descendant became King of Jerusalem) happily accepted Herleve as a suitable Guardian for his daughter. (cited by Searle E, Jumieges') Herelev's father was later promoted to Yeoman of the Chamber ( see Professor Montogomery's lectures on the Norman Conquest.
Herleve later married Herluin, Vicomte de Conteville, by whom she had at least two sons – Odo, later Bishop of Bayeaux and Robert, later Count of Mortain who married Maud de Montgomery, daughter of Roger de Montgomery
Thus, William the Bastard, despite his illigitamacy, had some claim to 'uterine nobility' as his mother, far rom being the daughter of a tanner, was a member of the petit noblesse.