William Simmons

(male) 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.

English (southern): patronymic either from the personal name Simon (see Simon) or, as Reaney and Wilson suggest, from the medieval personal name Simund (composed of Old Norse sig ‘victory’ + mundr ‘protection’), which after the Norman Conquest was taken as an equivalent Simon, with the result that the two names became confused.