The cinematic portrayal of Guinevere as a Celtic warrior who joins Arthur's knights in battle is a drastic alteration from the demure "damsel in distress" of courtly romance. Although there is historical and mythological precedent for "sword-swinging warrior queens", such as the British Boudica of the Iceni, Gwenllian ferch Gruffydd of Wales, or the various Celtic war goddesses, the film's portrayal of Guinevere is actually closer to the Queen Medb of the Irish "Táin Bó Cúailnge". However, no source, early or late, describes Guinevere as either a warrior or a rustic Celt; in fact, in Geoffrey of Monmouth's "Historia Regum Britanniae", which contains one of the oldest accounts of the character, Guinevere has Roman blood while Arthur is an indigenous Celt.