Before becoming Pope Alexander VI in 1492, this man was known by this name.
Guiliano della Rovere
Before becoming Pope Alexander VI in 1492, this man was known as Rodrigo Borgia. He arrived in Rome from Spain in 1449 and Italianized his name from Borja (pronounced Bor-ha) to Borgia (Bor-ja). His rise in the church was helped a great deal when his uncle became Pope Calixtus III.