Rafael painted dirty episodes from classical mythology in a bathroom at the vatican palace (sadly these are lost).
We were much interested in the vatican palace, the residence of the Pope.
Nicholas the Fifth died in 1455, and the oldest parts of the present vatican palace are not older than his reign.
1550s, from Latin mons Vaticanus, Roman hill on which Papal palace stands. An Etruscan loan-word, not related to vates "sooth-sayer."