In his Divine Comedy, Dante mentions some historical figures from the province of Viterbo who really existed, such as Saint Bonaventure of Bagnoregio, and he focuses particularly on events that took place in the city.
The passage describing the death of Henry of Cornwall (grandson of King Henry III), killed by Guy de Montfort (vicar-general of Charles d’Anjou in central Italy) in the Church of Gesù in Viterbo is particularly famous.
Dante placed Guy in Inferno (where the River Phlegethon flows, here compared to Bulicame – the thermal waters of Viterbo), among murderers, showing just how shocking this event was to the public at the time. A great archbishop, remembered especially for his involvement in political upheavals in Pisa, and buried in Viterbo, is also mentioned by Dante: this was Ruggieri degli Ubaldini, who, with cunning political manoeuvring, managed to rid the Tuscan city of the Guelph chiefs – in particular, his adversary Ugolino della Gherardesca.
Dante is no less generous with him, condemning him to eternity to Inferno, in Antenora, among traitors of one’s country.
Among the Popes native to Viterbo, Dante mentions five: Pope Clement IV, with reference to the dearth of Manfredi; Nicholas III, among those accused of committing simony; Hadrian V placed among the avaricious; and Martin IV, in Purgatory among the glutton on account of his well-known passion for eels from Lake Bolsena.
The only pope to whom Dante shows a measure of leniency is the Portuguese (the only one in history) John XXI, raised to Paradise among the great scholars on account of his theological works.