A Roman general (d. AD 432) active in N Africa. See generally PLRE 2.237-40, under Boniface(3); OCD(3) p.249. 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.