If the Apostolic Tradition is the work of Hippolytus of Rome, it could be dated before 235 CE (when Hippolytus is believed to have suffered martyrdom) and its origin would be Rome; this date has been defended in recent scholarship by Brent and Stewart. Against this, other scholars (see Bradshaw) believe that the key liturgical sections incorporate material of separate sources, some Roman and some not, ranging from the middle second to the fourth century, being gathered and compiled on about 375-400 CE, probably in Egypt or even Syria. Against this, other scholars have suggested that the "Apostolic Tradition" portrays a liturgy that was never celebrated.