Dante, speaking with Cacciaguida, uses the formal "voi" — the honorific plural — for the only time in the poem. Beatrice smiles at this moment of pride in ancestry, as if to say: even here, even now, the old vanities flicker. Dante notices her smile and is briefly sheepish. But the conversation is deeply important to him: this is his family, his blood, his city as it was before his exile destroyed it for him.
Cacciaguida gives biographical details: his birth date (under Mars, 1091 or so), his wife from the Po valley, the origin of the name Alighieri from her family. He then catalogs the neighborhoods and families of his Florence — the Mercato Vecchio, Borgo Santi Apostoli, the ancient towers and clans. The names ring out like a toll of lost things: the Ravignani, the Fifanti, the Caponsacchi, the Gualterotti, the Importuni. Some of these families have declined into shame; others are extinct. Cities, like people, are mortal. Florence's corruption and self-destruction were already predictable in the pattern of its families' histories.
Cacciaguida particularly blames the mixing of the old city with newcomers brought in from the surrounding countryside — the Cerchi from Acone, the Buondelmonti from Valdigreve — whose arrival disrupted the stable social order. From the Buondelmonti family's quarrel over a broken betrothal came the Guelf-Ghibelline split that ruined Florence. He names the moment: if God had drowned that family before their fatal quarrel, Florence would be at peace. The tone is elegiac, precise, and political all at once.