Complex sentence: In 1644, Costa left Florence and returned to Rome under the protection of Cardinal Francesco Barberini, to whom she dedicated a sacred poem about the Roman Saint Cecilia, the patron saint of music.
Split into simpler sentences: In 1644, Costa left Florence and returned to Rome. Here she cultivated a relationship with Francesco Barberini, to whom she dedicated a sacred poem about the Roman Saint Cecilia, the patron saint of music.