Gian Lorenzo Bernini and Francesco Borromini were the most important architects in Rome in the 17th century. Due to the multiplicity and the importance of their works, we want to dedicate two different routes to them. Bernini and Borromini got to know each other during the papacy of Pope Urban VIII. (1623-1644), who employed both artists for the projects of his new family palace near to the Quirinal and for inner decoration of the new St. Peter’s. Far more than Borromini, who was provided only with smaller decorative works, should the name of Bernini, who was appointed chief director of both commissions, be irrevocably connected with St. Peter’s? Apart from the triumphal baldachin over the grave of the apostle Peter, Bernini also realized the scenographic Cattedra Petri in the apsis and the monumental square before the church, commissioned by Pope Alexander VII. The difficult and introverted character of Borromini, who committed suicide in 1667, was probably the reason for the fact that he was enlisted by the Popes for fewer commissions than the society-loving Bernini, whose splendid sculptural and architectural works corresponded exactly with the taste of his times. Borromini was more often employed by private fraternities: for the Filippini he realized the beautiful facade of the oratory, that together with the adjoining church and convent, formed the centre of Filippo Neri’s religious order, founded in 1575. Under Innocent X Pamphilj (1644-1655) the “rivals” Bernini and Borromini worked side by side again: while Borromini designed the church S. Agnese in Agone beside the Pamphili Palace in the Piazza Navona, Bernini realized the famous Fontana dei Quattro Fiumi in front of the church. Our tour will then lead us to one of Borromini’s masterpieces: the church S. Ivo alla Sapienza, constructed inside the courtyard of Rome’s former university. The itinerary ends in front of Bernini’s facade of the Palazzo di Montecitorio, which is today’s seat of parliament.