Probably the most successful of all the Old French names of Germanic origin that were introduced to England by the Normans. It is derived from Germanic wil ‘will, desire’ + helm ‘helmet, protection’. The fact that it was borne by the Conqueror himself does not seem to have inhibited its favour with the ‘conquered’ population: in the first century after the Conquest it was the commonest male name of all, and not only among the Normans. In the later Middle Ages it was overtaken by John, but continued to run second to that name until the 20th century, when the picture became more fragmented.
German (also Knöpf) and Jewish (Ashkenazic): from Middle High German knopf ‘swelling’, ‘lump’, ‘knob’, ‘button’, ‘glob’, modern German Knopf, hence a metonymic occupational name for a maker of buttons, normally of horn; a nickname for a small, rotund man (especially in Swabia, where the term also has the sense ‘dumpling’); or a topographic name for someone who lived by a rounded hillock.