The basilica was commissioned by the Florentine community in Rome. The construction began in the 16th century and was mainly executed by Giacomo della Porta. The church is dedicated to Saint John the Baptist, the patron saint of Florence. Borromini collaborated on the building and the burial sites of the Falconieri family. The base and the oval-shaped alcove are by him. Subsequent decorative additions and statues distort his style. The church was completed in the 18th century but the original design envisioned by Borromini remains unknown.