From an Old French name, of Germanic (Frankish) origin, originally a short form of a compound name starting with witu ‘wood’ or wīt ‘wide’. This was adopted by the Normans and introduced by them to England. In Old French initial w- regularly became gu-. The usual Norman forms of the name were Gy or Guido. In medieval Latin the same name is found as Wido. It was a popular name among the Normans, enhanced no doubt by the romance of Guy of Warwick, recounting the exploits of a folk hero of the Crusades.