Rome, early 16th century : Imperia is a much admired courtesan , a lover of the wealthy banker Agostino Chigi , but who prefers a man named Angelo del Bufalo , known for his charm and beauty , capable of striking women , despite his its modestwealth, known during a dance at the family palace near Castel Sant'Angelo, known today as the Villa Farnesina . Cesare Borgia , involved in the murder of his brother Juan, and his sister also participate in the inauguration party of the new home of the Chigi family on the TiberLucrezia with her husband Alfonso. During the party, Imperia dances with several knights, until she reaches the arms of a knight who the day before had saved her from a bad encounter with two brigands: that knight is just her angel, with whom she establishes a relationshipsecret. .