Pope Sixtus V's Commission
Monte Cavallo Fountain
Here, in front of the Quirinale Palace, you cannot miss the two colossal statues of the Dioscuri (Castor and Pollux), with their horses rearing up beside them, as they face the palace in an attitude that seems to be somewhere between the haughty and the horrified. These statues appear on all the old maps of Rome and all the city guides as far back as the 1400s.
The statues of Castor and Pollux have always been in more or less the same place as we see them now. Originally, they were turned toward and lined up exactly with Constantine's Baths, which lay just about where the Palazzo della Consulta is today. So the statues stood at the very end of the old road called Alta Semita. Following the energetic leveling works carried out under Pius IV in 1561, this became known as Strada Pia (now Via del Quirinale and Via XX Settembre). Strada Pia stretched out past Porta Pia to the Nomentano Bridge for the space of three miles from the horses of Tiridatus -- in other words, the Dioscuri. The arrangement remained that way until the time of Sixtus V (1589).
Pope Sixtus V disliked the location of the statues facing the ruins of the ancient baths. A major factor was that, despite their imposing size, the statues made no impression on anyone approaching from Porta Pia as, from that direction, they were difficult to see. So, taking advantage of the talents of his usual favorite artist, Domenico Fontana, Pope Sixtus had the group moved back and turned around to face Strada Pia. When it came to hauling huge "chunks of old junk" around the city, Fontana did not need telling twice -- after all, he had already transported four colossal obelisks across Rome.
Here is how Fontana described the task: Sixtus V had me move the horses of Praxiteles and Phidia all damaged and corroded with age into a more dignified location opposite the opening of Strada Pia. I had to restore a large part of their bodies and limbs because they were missing and I made marble pedestals for them, with the following inscriptions newly cut around them in archaic capital letters; and all with the greatest care and at very great expense.
I will not say much about the inscriptions because for one, they have nothing to do with the fountain and, for another, they no longer exist. However, I should be unhappy if you did not know that Pope Urban VIII had the two old inscriptions that were beneath the horses removed in 1634. Experts at that time ascertained that, contrary to the wording of the inscription ordered by Sixtus V, the two groups representing both Alexander the Great and his horse Bucephalus either were not the work of the Greek sculptors Phidia and Praxiteles (for the simple reason that these people lived 100 years before Alexander) or it was impossible that the statues were portraits of him and his horse Bucephalus.
After referring to the long inscriptions, Fontana continued: In the same place [Sixtus V] leveled and enlarged a fine square to serve the Consistories that take place at Monte Cavallo, to such an extent that it has become very beautiful and can hold very many people, and he has had a public fountain put there with an excellent abundance of water, and has leveled Strada Pia. As we have seen, the first stage of the conduits bringing the Aqua Felice to the Capitoline Hill was marked by the Four Fountains which, at the time in 1590 still numbered only three. Sixtus now wanted Master Domenico to build him a beautiful stone fountain at the other end of that same Strada Pia, against the backdrop of "Fidie and Presitelli" (as a contemporary document called the two restored colossi). You can see what this fountain used to look like from a few sketches made a good many years apart. A large octagonal travertine base with two steps leads to an irregularly shaped basin. On the outside of the basin, alternating with Sixtus's coat-of-arms, four lion's heads spout water into a channel cut into the base itself.
