Actually one of the greatest of literary tricks: Boniface wasn't dead in 1300 when the Inferno takes place (he was dead [d. 1303] when Dante wrote / published his work), so Dante the author has Dante the pilgrim / persona (in his 1300 fictional journey) encounter Pope Nicholas III among the simonists in Circle 8, and Nicholas (who is immersed face down in a baptismal font and can't see anything, a punishment befitting anyone who inverted the sacred and the secular--i.e. monetary gain--Circle8 is for fraud or lying) assumes Dante and Virgil are the next simonist who will replace him and asks "Is that you, Boniface?"

The real Boniface (in a political machination) colluded to have Dante exiled from Florence. Woe to anyone on Dante's bad list.