Robert Bellarmine was an Italian Jesuit and a Cardinal of the Catholic Church. He participated in the Church's proceedings against Giordano Bruno (sentencing him to be burned alive in a public square) and Galileo Galilei (who escaped the same fate, with eleven years' house imprisonment).
By the time Bellarmine was in his 60s, he bore a resemblance to the First Doctor so that Irving Braxiatel's Jamarian agents mistook the Cardinal for the Doctor. They abducted him to moderate the Armageddon Convention. The fact that the Doctor was impersonating the Cardinal to protect himself and secure the protection of the Venice government further complicated matters.
Believing he had died and that Braxiatel's Laputa was Heaven, Bellarmine could only understand his experiences among aliens through his Christian faith. He concluded that the aliens were angels and he was being asked to mediate a war in heaven. He believed the Doctor had settled many of their disputes, so his rulings satisfied the delegates to the Convention and were accepted. (PROSE: The Empire of Glass)