Pantheon         

The spherical roof of the Pantheon was originally gilded in bronze. This surface survived well over 1000 years, and was then apparently looted along with the bronze portico trusses by Pope Urban VIII for other structures, including the ridiculous baldacchino of St. Peter's. This inspired the famous graffito, Quod non fecerunt barbari fecerunt Barberini. Barberini was the family name of Urban VIII, thus the Latin proverb states that what the barbarians didn't do, the Barberini did.
Some sources (e.g. Platner, 1929) claim that it was Emperor Constans who removed the bronze, however Lanciani (1897) quotes Giacinto Gigli, Urban's diarist, who describes the act, and gives the weight of the removed bronze as 450,251 pounds.