On the western façade of the Ara, next to the panel of Aeneas, a few fragments extracted from the foundations of the Palazzo Fiano-Almagià during the excavations of 1859, 1903 and of 1937, have allowed us to recognize the representation of the other topical moment of Rome’s foundation myth: Romulus and Remus suckled by the she-wolf under the attentive eyes of the shepherd Faustulus, who will adopt and bring up the twins, and of Mars, the god who generated them when he coupled with the vestal Rhea Sylvia. So, in the same years when Augustus was restoring the actual place of the Lupercal, the cave at the foot of the Palatine consecrated to Mars and to Faunus Lupercus, thus reviving the relative ancient rituals, the Romans could also admire on the Ara Pacis the “devotional” picture of their legendary origins. That definition is provided by Paul Zanker, who rightly underlines the sacred dimension and the indefinite atmosphere of the two interrelated panels, that of Aeneas and that of the Lupercal. They were presented to the worship of those who would walk across the Campus Martius, according to the Augustan programme of religious and moral reform (Zanker 1989). In the middle of the composition stands the fig tree, the ficus ruminalis (from rumae, mammals) that frames the scene of the suckling. On the surviving fragment of the tree one can distinguish the talons of a bird, that was restored in 1938 as an eagle, but that is more likely to be a woodpecker, a totemic animal that appears in the cults of ancient Latium, connected with the sky’s symbol of the lightning and, like the she-wolf, sacred to Mars. To the right of the fig tree is the shepherd Faustulus, of whom one can still see the right arm resting on a staff, part of the bust, of the drapery and, much damaged, the lower part of the head. Faustulus descends, according to the legend, from Evandrus, king of the Arcades, who peopled the Palatine even before Rome was founded: his providential presence near the twins symbolically confirms the bond of ancient friendship and hospitality clenched by Aeneas’ descendants with the local populations. To the left of the tree, Mars appears to entrust his offspring to Faustulus. The god is depicted in his warlike garb: a spear in his left hand, he’s wearing a crested helmet ornamented with a griffin, and a cuirass on which the winged head of a Gorgon can clearly be distinguished. Unfortunately, only the right foot and a bent knee, appearing from under a short tunic, are left.

The events concerning the rescue of the head of Mars, undoubtedly the most significant fragment of the whole composition, deserve to be mentioned. The head was unearthed in 1859, during the works carried out to stabilize the palace near San Lorenzo in Lucina, ordered by the duke of Fiano. The head was then sold, in the absence of laws concerning the export of works of art, to a private collector, and taken to Vienna. In a second moment, Petersen realized that it belonged to the Ara Pacis and hence the Italian Government managed to reacquire it in 1898, and placed it in the newly created Museo delle Terme. Only after 1903—when the few scattered pieces of the ficus ruminalis were rescued and, through them, the scene of the Lupercal could eventually be recognized—Studniczka correctly connected the head with such mythical scene. During the 1937 excavaton some fragments of the cuirass, of the knee and some less significant pieces were finally rescued, so a year later the scene of the Lupercal was completed on the basis of known examples with a similar iconography by sketching its outline. This was probably done by the same restorer, Ferretti, whose hand had already integrated the panel with the goddess Rome.