A spirit detaches itself from the great cross and descends along one arm toward Dante — like a flame shooting along a sky. It speaks in Latin from Virgil and the Aeneid, greeting Dante as blood of its blood. Dante does not yet understand who it is. The soul, almost overwhelmed with joy, falls silent — then explains that it has been waiting for this meeting since the beginning of Dante's mortal life, reading it in the great book where nothing changes (the mind of God), longing to speak with him. God gave it this gift.
The soul is Cacciaguida — Dante's great-great-grandfather, a Florentine knight of the 12th century who was made a knight by Emperor Conrad III, fought in the Second Crusade, and was martyred in the Holy Land. The meeting is one of the most emotionally central in the poem — Dante's one encounter with a blood ancestor, and one of the few times any soul in the Commedia addresses him with deep personal love and knowledge.
Cacciaguida then speaks of old Florence with an ache of nostalgia that is also a polemic. Florence in his day was smaller, simpler, uncorrupted by the new wealth of the merchant class. Women were modest; no one wore jewels that outranked their station. Men were proud of their families in the old way. The city was contained within the old walls; it had not yet swollen with the influx of newcomers who have corrupted its character. He names the old families — the Figuiovanni, the Sacchetti, the Giuochi, the Fifanti — like a man mourning the dead. The Florence Dante was exiled from was already corrupt; the Florence Cacciaguida knew was something else entirely.