Actually a Norman thing. originally it would have been pronounced Bee-vwah.
From Wiki:
Bevis of Hampton is a legendary English hero and the subject of an English metrical romance that bears his name.
Bevis is the son of Guy, count of Hampton (Southampton) and his young wife, a daughter of the king of Scotland. The countess asks a former suitor, Doon or Devoun, emperor of Almaine (Germany), to send an army to murder Guy in the forest. The plot is successful, and she marries Doon. When threatened with future vengeance by her ten-year-old son, she determines to make away with him also, but he is saved from death by a faithful tutor, is sold to heathen pirates, and reaches the court of King Hermin, whose realm is variously placed in Egypt and Armenia (Armorica). The exploits of Bevis, his defeat of Ascapart, his love for the king's daughter Josiane, his mission to King Bradmond of Damascus with a sealed letter demanding his own death, his imprisonment, his final vengeance on his stepfather are related in detail. After succeeding to his inheritance he is, however, driven into exile and separated from Josiane, to whom he is reunited only after each of them has contracted, in form only, a second union. The story also relates the hero's death and the fortunes of his two sons.
The oldest extant version appears to be Boeve de Haumtone, an Anglo-Norman text which dates from the first half of the 13th century. The English metrical romance, Sir Beues of Hamtoun, is founded on some French original varying slightly from those which have been preserved. The oldest manuscript dates from the beginning of the 14th century. The French chanson de geste, Beuve d'Hanstone, was followed by numerous prose versions. The printed editions of the story were most numerous in Italy, where Bovo or Buovo d'Antona was the subject of more than one poem, and the tale was interpolated in the Reali di Francia, the Italian compilation of Carolingian legend. From Italian, it passed into Yiddish, where the Bovo-Bukh became the most popular and most critically honored Yiddish-language chivalric romance.
In Russia, the romance attained an unparalleled popularity and became a part of Russian folklore. The Russian rendition of the romance appeared in mid-XVI century, translated from a Polish or Old Byelorussian version, which were, in turn, translated from a Serbocroatian rendition of the Italian romance, made in Ragusa. The resulting narrative, called Повесть о Бове-королевиче (Povest' o Bove-koroleviche, lit. The Story of Prince Bova), gradually merged with Russian folktales, and the principal character attained many features of a Russian folk hero (bogatyr). Since the 1700s until 1918, various versions of the Povest' had been widely circulated (particularly among the lower classes) as a lubok. Such writers as Derzhavin and Pushkin praised Bova's literary value; the latter used some elements of the Povest' in his fairy tales and attempted to write a fantasy poem based on the romance.
Although the English version that we possess is based on a French original, it seems probable that the legend took shape on English soil in the 10th century, and that it originated with the Danish invaders. Doon may be identified with the emperor Otto the Great, who was the contemporary of Edgar Atheling, the English king Edgar of the story. R. Zenker (Boeve-Amlethus, Berlin and Leipzig, 1904) establishes a close parallel between Bevis and the Hamlet legend as related by Saxo Grammaticus in the Historia Danica.
Among the more obvious coincidences which point to a common source are the vengeance taken on a stepfather for a father's death, the letter bearing his own death-warrant which is entrusted to the hero, and his double marriage. The motive of the feigned madness is, however, lacking in Bevis. The princess who is Josiane's rival is less ferocious than the Hermuthruda of the Hamlet legend, but she threatens Bevis with death if he refuses her. Both seem to be modelled on the type of Thyrdo of the Beowulf legend. The 1911 Encyclopædia Britannica characterizes the mooted etymology connecting Bevis (Boeve) with Béowa (Beowulf), on the ground that both were dragon slayers, as "fanciful" and "inadmissible".
