I followed the app, Visit a City, for their recommended sights to see in Viterbo to the letter for the 4-hr version. First Palazzo dei Papi. The Papal administrative body (Papal Curia) was moved from Rome to Viterbo in 1257 and remained until 1281. The papacy was in the midst of great political instability thereafter and moved to several other sites including Avignon in 1309.
What really fascinated me was that when the cardinals were required to elect a new pope here in Viterbo following the death of Pope Clement IV in 1268,
they were taking so long to pick a new pope that their presence was bankrupting local Viterbo businesses. That, apparently, drove the infuriated local people to lock the cardinals inside the palace and to remove the palace roof, exposing those inside to the elements. They vowed only to unlock the door once a decision had been reached. This was the beginning of the “conclave” process (i.e., with key). BTW, the first Pope elected at Viterbo took almost three years!
Secondly, I went next door (with the same audio set) to the Viterbo Cathedral built at the site of an Etruscan Temple.
Lastly I saw the ancient Romanesque Church Santa Maria Nuova followed by a visit to the San Pellegrino District of Viterbo that’s known for its well-preserved medieval buildings.
