Medieval times, brought neglect to the area where the fountain presently stands, although the temple of all gods (Pantheon), thanks to being transformed into a church dedicated to Our Lady of Martyrs (Santa Maria ad Martyres) escaped demolition. The square named from the rotund shape of this structure, Piazza della Rotonda, in time began to serve the citizens as a marketplace, on which vegetables and fish were sold. All the papal decrees, which were supposed to restore order to this place and change it into a representative square which would be more fit for a Catholic church, came to nothing. It was not until the XV century when it was paved with travertine and enriched with a porphyry bowl from the former Temple of Isis, and flanked by two stone lions. Thanks to restoring the ancient Aqua Virgo aqueduct, water was brought to the square, which inspired the following pope, Gregory XIII, to entrust the architect Giacomo della Porta, with the creation of a design of eighteen fountains, which were to stand on the path of this waterway. At that time, in 1575, the a bowl with high edges, made of African marble was placed on Piazza della Rotonda. Four mascarons, along with dolphins, which were first destined for a different fountain (Fontana del Nettuno), ultimately found their place here. They were sculpted by Leonardo Sormani. At that time the fountain was far removed from its present-day splendor, nevertheless it constituted a new, decorative element of this location. In 1711, this time at the behest of Pope Clement XI, an obelisk was added to it (Macuteo Obelisk), made of pink granite, and dating all the way back to the times of pharaoh Ramses II. The principal designer of the modernization, Filippo Barigioni, had to face quite a challenge in order to meet the pope’s expectations. A not too soaring obelisk made up a composition of imperfect proportions. The solution, was found by the artist, looking at the works of the unmatched genius of the previous century, Gian Lorenzo Bernini, and his fountain (Fontana dei Quattro Fiumi). He only needed to raise the base, in order for the obelisk, which was to stand upon it, to look truly monumental. His creation also did not lack elements reminiscent of rocks and it is from them that the fountain construction stretches upwards. The whole is topped off with a multi-pointed star, one of the emblems of the coat of arms of the Albani family, from which Clement XI came. On the other hand the papal coat of arms (star and three mountains) can be seen on the plinth of the fountain, surrounded by dolphins – the work of the sculptor Vincenzo Felici. The last act was not added to the fountain until 1880. The mascarons damaged over time, were exchanged with their copies, and a woman’s head was added, supported by the dolphins’ beaks.

Today the fountain is truly beautiful – situated on a pedestal with a form of a water reservoir, enriched by steps, it seems to be a homogenous work, and yet it is as the whole of Rome itself, an ever-growing creation  taking on its shape through the ages.