Plut.) a small river which flows into the Tiber, on its left bank, about 11 miles N. of Rome.
It was on its banks that the Romans sustained the memorable defeat by the Gauls under Brennus in B.C. 390, which led to the capture and destruction of the city by the barbarians. On this account the day on which the battle was fought, the 16th of July (xv. Kal. Sextiles), called the Dies Alliensis,
was ever after regarded as disastrous, and it was forbidden to trans. act any public business on it. (Liv. 6.1
; Verg. A. 7.717
; Tac. Hist. 2.91
; Varr. de L.L.
6.32; Lucan 7.408
; Cic. Ep. ad Att. 9.5
; Kal. Amitern. ap. Orell. Inscr. vol. ii. p. 394.)
A few years later, B.C. 377, the Praenestines and their allies, during a war with Rome, took up a position on the Allia, trusting that it would prove of evil omen to their adversaries; but their hopes were deceived, and they were totally defeated by the dictator Cincinnatus. (Liv. 6.28
; Eutrop. 2.2
The situation of this celebrated, but insignificant, stream is marked with unusual precision by Livy: “Aegre (hostibus) ad undecimum lapidem occursum est, qua flumen Allia Crustuminis montibus praealto defluens alveo, hand multum infra viam Tiberino amni miscetur.” (5.37.) The Gauls were advancing upon Rome by the left bank of the Tiber, so that there can be no doubt that the “via” here mentioned is the Via Salaria, and the correctness of the distance is confirmed by Plutarch( Camill.
18), who reckons it at 90 stadia, and by Eutropius (1.20
), while Vibius Sequester, who places it at 14 miles from Rome (p. 3), is an authority of no value on such a point. Notwithstanding this accurate description, the identification of the river designated has been the subject of much doubt and discussion, principally arising from the circumstance that there is no stream which actually crosses the Via Salaria at the required distance from Rome. Indeed the only two streams which can in any degree deserve the title of rivers, that flow into this part of the Tiber, are the Rio del Mosso,
which crosses the modern road at the Osteria del Grillo
about 18 miles from Rome, and the Fosso di Conca,
which rises at a place called Conca
(near the site of Ficulea), about 13 miles from Rome, but flows in a southerly direction and crosses the Via Salaria at Malpasso,
not quite 7 miles from the city.
The former of these, though supposed by Cluverius to be the Allia, is not only much too distant from Rome, but does not correspond with the description of Livy, as it flows through a nearly flat country, and its banks are low and defenceless. The Fosso di Conca
on the contrary is too near to Rome, where it crosses the road and enters the Tiber; on which account Nibby and Gell have supposed the battle to have been fought higher up its course, above Torre di S. Giovanni.
But the expressions of Livy above cited and his whole narrative clearly prove that he conceived the battle to have been fought close to the Tiber, so that the Romans rested their left wing on that river, and their right on the Crustumian hills, protected by the reserve force which was posted on
one of those hills, and against which Brennus directed his first attack. Both these two rivers must therefore be rejected; but between them are two smaller streams which, though little more than ditches in appearance, flow through deep and narrow ravines, where they issue from the hills; the first of these, which rises not far from the Fosso di Conca,
crosses the road about a mile beyond La Marcigliana,
and rather more than 9 from Rome; the second, called the Scolo del Casale,
about 3 miles further on, at a spot named the Fonte di Papa,
which is just more than 12 miles from Rome.
The choice must lie between these two, of which the former has been adopted by Holstenius and Westphal, but the latter has on the whole the best claim to be regarded as the true Allia.
It coincides in all respects with Livy's description, except that the distance is a mile too great; but the difference in the other case is greater, and the correspondence in no other respect more satisfactory. If it be objected that the little brook at Fonte di Papa
is too trifling a stream to have earned such an immortal name, it may be observed that the very particular manner in which Livy describes the locality, sufficiently shows that it was not one necessarily familiar to his. readers, nor does any [p. 1.105]
mention of the river Allia occur at a later period of Roman history. (Cluver. Ital.
p. 709; Holsten. Adnot.
p. 127; Westphal, Römische Kampagne,
p. 127; Gell's Top. of Rome,
p. 44-48; Nibby, Dintorni di Roma,
vol. i. p. 125; Reichard, Thesaur. Topogr.