Transliteration of a Latin name: a Roman general (d. 432 CE) active in N Africa. See generally PLRE 2.237-40, under Boniface(3); OCD(4) p.239. Or perhaps a saint of this name: Boniface of Tarsus is commemorated for his martyrdom in the reign of Diocletian (sermon by Ephraim the Syrian), and Socrates' Ecclesastical History mentions Boniface I as bishop of Rome (4th century).
cf. ps.-Herodian 8, and (according to Adler) the Ambrosian Lexicon.