Sordello and Virgil recognize each other as Mantuans, though separated by more than a thousand years — Sordello (c. 1200–1269) died after Virgil (70 BC–19 AD). The conversation turns to where Virgil dwells: Limbo, where he is not in torment but cannot ascend. Sordello is struck by reverence. The scene quietly illustrates Purgatorio's expansion of moral community across time — the classical and the medieval in dialogue.
The sun is setting. Sordello explains a crucial rule of Purgatory: souls cannot travel upward after sunset. The darkness does not block them physically but spiritually — without the light, the will is weakened and the climb impossible. They must wait for dawn. He leads them instead to the Valley of Negligent Princes, a hidden hollow fragrant with flowers of every color, filled with souls singing the Salve Regina (the hymn to the Virgin Mary) in the twilight.
Sordello identifies the gathered rulers of Europe one by one, and his commentary is pointed. Rudolph of Habsburg sits apart, neglectful of Italy that he might have healed. Ottokar of Bohemia is there — a better man than his son Wenceslaus. Philip III of France and Henry of Navarre are side by side — both in their way failures of governance. Henry III of England, a man of simple character, sits with Philip III. Peter III of Aragon is praised lavishly: better than all his contemporaries. The catalogue is simultaneously a lesson in medieval European politics and a meditation on how greatness rarely descends from parent to child — "seldom does human excellence rise through the branches," Sordello observes. The virtue of a father need not pass to his sons.