), a small river on the E. coast of Italy, flowing into the Adriatic sea, a few miles N. of Ariminum.
It was a trifling stream, one of the least considerable of the numerous rivers that in this part of Italy have their rise in the Apennines, and discharge their waters into the Adriatic; but it derived some importance from its having formed the boundary between Umbria, or the part of the Gaulish territory included in that province. and Cisalpine Gaul, properly so called. Hence, when the limits of Italy were considered to extend only to the frontiers of Cisalpine Gaul, the Rubicon became on this side the northern boundary of Italy. (Strab. v. p.217
; Plin. Nat. 3.15. s. 20
; Lucan 1.215
This was the state of things at the outbreak of the Civil War between Caesar and Pompey: Cisalpine Gaul was included in the government of the former, and the Rubicon was therefore the limit of his province; it was this which rendered the passage of this trifling stream so momentous an event, for it was, in fact, the declaration of war. Caesar himself makes no mention of its passage, and it is difficult to believe that he would have set out on his march from Ravenna without being fully prepared to advance to Ariminum; but the well-known story of his halt on its banks, his hesitation and ultimate decision, is related in detail by Suetonius and Plutarch, as well as by Lucan, and has given a proverbial celebrity to the name of the Rubicon. (Suet. Jul. 31
; Plut. Caes. 32
; Appian, App. BC 2.35
; Lucan 1.185
The river is alluded to by Cicero a few years later as the frontier of Gaul; and M. Antonius was ordered by a decree of the senate to withdraw his army across the Rubicon, as a proof that he abandoned his designs on the Gaulish province. (Cic. Phil. 6.3
) Strabo still reckons the Rubicon the limit between Gallia Cisalpina and Umbria; but this seems to have been altered in the division of Italy by Augustus; and though Pliny alludes to the Rubicon as “quondam finis Italiae,” he includes Ariminum and its territory as far as the river Crustumius, in the 8th Region or Gallia Cispadana. (Plin. l.c.; Ptol. 3.1.23
.) Its name, however, was not forgotten; it is still found in the Tabula, which places it 12 miles from Ariminum (Tab. Peut.
), and is mentioned by Sidonius Apollinaris. (Ep.
But in the middle ages all trace of it seems to have been lost; even the Geographer of Ravenna does not notice it, notwithstanding its proximity to his native city.
In modern times the identification of this celebrated stream has been the subject of much controversy, and cannot yet be considered as fully determined.
But the question lies within very narrow compass. We know with certainty that the Rubicon was intermediate between Ariminum and Ravenna, and between the rivers Sapis (Savio
), which flowed some miles S. of the latter, and the Ariminus or Marecchia,
which was immediately to the N. of the former city. Between these two rivers only two streams now enter the Adriatic, within a very short distance of each other.
The southernmost of these is called the Luso
a considerable stream, which crosses the high-road from Rimini
about 10 miles from the former city.
A short distance further N. the same road crosses a stream now called Fiumicino,
which is formed by the united waters of three small streams or torrents, the most considerable of which is the Pisatello
(the uppermost of the three); the other two are the Rigosa
called also, according to some writers, the Rugone,
and the Plusa,
called also the Fiumicino.
These names are those attested by the best old maps as well as modern ones, especially by the Atlas of Magini, published in 1620, and are in accordance with the statements of the earliest writers on Italian topography, Flavio Biondo and Leandro Alberti. Cluverius, however, calls the northernmost stream the Rugone,
and the one next to it the Pisatello.
This point is, however, of little importance, if it be certain that the two streams always united their waters as they do at the present day before reaching the sea.
The question really lies between the Luso
and the Fiumicino,
the latter being the outlet both of the Rugone
and the Pisatello.
A papal bull, issued in 1756, pronounced in favour of the Luso,
which has, in consequence, been since commonly termed the Rubicon, and is still called by the peasants on its banks Il Rubicone.
But it is evident that such an authority has no real [p. 2.857]
The name of Rugone,
applied to one of the three branches of the Fiumicino,
would be of more value, if it were certain that this name had not been distorted by antiquarians to suit their own purposes.
But it appears that old maps and books write the name Rigosa.
Two arguments, however, may be considered as almost decisive in favour of the Fiumicino
as compared with the Luso:
The distance given in the Tabula of 12 miles from Ariminum, coincides exactly with the distance of the Fiumicino
from that city, as stated by Cluverius, who examined the question on the spot; and 2ndly, the redness of the gravel in the bed of the stream, from which it was supposed to have derived its name, and which is distinctly alluded to by Sidonius Apollinaris, as well as by Lucan (Sidon. Ep.
1.5; Lucan 1.214
), was remarked by Cluverius as a character of the Fiumicino,
which was wholly wanting in the Luso.
The circumstance which has been relied on by some authors, that the latter river is a more considerable and rapid stream than the other, and would therefore constitute a better frontier, is certainly of no value, for Lucan distinctly speaks of the Rubicon as a trifling stream, with little water in it except when swollen by the winter rains.
The arguments in favour of the Fiumicino
(if we retain the name of the principal of its three confluents) thus appear decidedly to preponderate; but the question still requires a careful examination on the spot, for the statements of Cluverius, though derived from personal observation, do not agree well with the modern maps, and it is not improbable that the petty streams in question may have undergone considerable changes since his time: still more probable is it that such changes may have taken place since the time of Caesar. (Cluver. Ital.
pp. 296--299; Blondi Flavii Italia Illustrata,
p. 343; Alberti, Descrizione d'Italic,
p. 246; Magini, Carta di Romagna;
Mannert, Geographie von Italien,
vol. i. p. 234; Murray's Handbook for Central Italy
The older dissertations on the subject will be found in Graevius and Burmann's Thesaurus,
vol. vii. part 2.)