Commentary Par XV 31

While this 'light' does not choose to identify himself until [Par XV 135], it is perhaps good to have some sense of Dante's great-great-grandfather, who is speaking in this scene, 'of whose life nothing is known beyond what Dante himself tells us; viz. that he was born in Florence ([Par XV 130-133]) in the Sesto di Porta san Piero ([Par XVI 40-42]) about the year 1090 ([Par XVI 34-39]); that he belonged (possibly) to the Elisei, one of the old Florentine families which boasted Roman descent ([Par XV 136]; [Par XVI 40]); that he was baptized in the baptistery of San Giovanni in Florence ([Par XV 134-135]); that he had two brothers, Moronto and Eliseo ([Par XV 136]); that his wife came from the valley of the Po, and that from her, through his son, Dante got his surname of Alighieri ([Par XV 91-94], [Par XV 137-138]); that he followed the Emperor Conrad III on the Second Crusade, and was knighted by him ([Par XV 139-144]), and finally that he fell fighting against the infidel about the year 1147 ([Par XV 145-148])' (Cacciaguida).