Rome was the adopted hometown of the Borgia; they were originally from the Catalan region of Spain. The Roman branch of the Santacroce family had lived in Rome for a few centuries.

In this episode, Marcello visits some of the famous locations related to the Renaissance families, including the Santacroce Tower, Castel Sant'Angelo (Saint Angel Castle). He also traces the Passetto del Borgo , a fortified passage built by Pope Borgia in order to provide a safe emergency route to the castle.