"Ponte Nomentana is a solitary dilapidated bridge in the spacious green Campagna. Many ruins from the days of ancient Rome, and many watch-towers from the middle ages, are scattered over this long succession of meadows; chains of hills rise towards the horizon, now partially covered with snow, and fantastically varied in form and colour by the shadows of the clouds. And there is also the enchanting vapoury vision of the Alban hills, which change their hues like the chameleon, as you gaze at them—where you can see for miles little white chapels glittering on the dark foreground of the hills, as far as the Passionist Convent on the summit, and whence you can trace the road winding through thickets, and the hills sloping downwards to the lake of Albano, while a hermitage peeps through the trees."—Mendelssohn's Letters.
The hill immediately beyond the bridge is the Mons Sacer (not only the part usually pointed out on the right of the road, but the whole hillside), to which the famous secession of the Plebs took place in B.C. 549, amounting, according to Dionysius, to about 4000 persons. Here they encamped upon the green slopes for four months, to the terror of the patricians, who foresaw that Rome, abandoned by its defenders, would fall before its enemies, and that the crops would perish for want of cultivation. Here Menenius Agrippa delivered his apologue of the belly and its members, which is said to have induced them to return to Rome; that which really decided them to do so being the concession of tribunes, to be the organs and representatives of the plebs as the consuls were of the patricians. The epithet Sacer is ascribed by Dionysius to an altar which the plebeians erected at the time on the hill to Ζεὑς Δειμἁτιος.
A second secession to the Mons Sacer took place in B.C. 449, when the plebs rose against Appius Claudius after the death of Virginia, and retired hither under the advice of M. Duilius, till the decemvirs resigned.
Following the road beyond the bridge past the castle known as Casale dei Pazzi (once used as a lunatic asylum) and the picturesque tomb called Torre Nomentana,—as far as the seventh milestone—we reach the remains of the unburied Basilica of S. Alessandro, built on the site of the place where that pope suffered martyrdom with his companions Eventius and Theodulus, A.D. 119, and was buried on the same spot by the Christian matron Severina.[245] The plan of the basilica, disinterred 1856-7, is still quite perfect. The tribune and high altar retain fragments of rich marbles and alabasters; the episcopal throne also remains in its place.
The "Acts of the martyrs Alexander, Eventius, and Theodulus," narrate that Severina buried the bodies of the first two martyrs in one tomb, and the third separately—"Theodulum vero alibi sepelivit." This is borne out by the discovery of a chapel opening from the nave, where the single word "martyri," is supposed to point out the grave of Theodulus. A baptistery has been found with its font, and another chapel adjoining is pointed out as the place where neophytes assembled to receive confirmation from the bishop. Among epitaphs laid bare in the pavement is one to a youth named Apollo "votus Deo" (dedicated to the priesthood?) at the age of 14. Entered from the church is the catacomb called "ad nymphas," containing many ancient inscriptions and a few rude paintings.
Mass is solemnly performed here by the Cardinal Prefect of the Propaganda on the festival of St. Alexander, May 3, when the roofless basilica—backed by the blue Sabine mountains and surrounded by the utterly desolate Campagna—is filled with worshippers, and presents a striking scene. Beyond this a road to the left leads through beautiful woods to Mentana, occupying the site of the ancient Nomentum, and recently celebrated for the battle between the papal troops and the Garibaldians on Nov. 3, 1867. The conflict took place chiefly on the hillside which is passed on the right before reaching the town. Two miles further is Monte Rotondo, with a fine old castle of the Barberini family (once of the Orsini), from which there is a beautiful view. This place was also the scene of fighting in 1867. It is possible to vary the route in returning to Rome from hence by the lower road which leads by the (now broken) Ponte Salara.
If we re-enter Rome by the Porta Pia, immediately within the gates we find another Villa belonging to the Torlonia family. The straight road from the gate leads by the Termini to the Quattro Fontane and the Monte Cavallo. On the left, if we follow the Via de Macao, which takes its strange name from a gift of land which the princes of Savoy made to the Jesuits for a mission in China, we reach a small piazza with two pines, where a gate on the left leads to the remains of the Pretorian Camp, established by Sejanus, the minister of Tiberius. It was dismantled by Constantine, but from three sides having been enclosed by Aurelian in the line of his city-wall, its form is still preserved to us. The Pretorian Camp was an oblong of 1200 by 1500 feet; its area was occupied by a vineyard of the Jesuits till 1861, when a "Campo Militare" was again established here, for the pontifical troops.
"En suivant l'enceinte de Rome, quand on arrive à l'endroit où elle se continue par le mur du Camp des prétoriens, on est frappé de la supériorité de construction que présente celui-ci. La partie des murs d'Honorius qui est voisine a été refaite au huitième siècle. Le commencement et la fin de l'empire se touchent. On peut apprécier d'un coup d'œil l'état de la civilisation aux deux époques: voilà ce qu'on faisait dans le premier siècle, et voilà ce qu'on faisait au huitième, après la conquête de l'empire Romain par les Barbares. Il faut songer toutefois que cette époque où l'on construisait si bien a amené celle où l'on ne savait plus construire."—Ampère, Emp. i. 421.
Hence a road, three-quarters of a mile long, leads—passing under an arch of Sixtus V.—to the Porta S. Lorenzo (Ch. XIII.).