It was on January 10th, 49 B. C., allegedly, that Gaius Julius Caesar decided to cross the Rubicon – literally – and thus both to start a bloody civil war and to create a metaphor, for millennia to come, that describes the deliberate taking of a fatal step at a point of no return.

Rubicon. – Image source here.

The incident is reported in several ancient sources, but it is Suetonius who, in his Life of Julius Caesar, preserves the Latin version of the famous phrase ‘the die is cast’, alea iacta est, ‘the game is on’ (Suet. Iul. 31–32, transl. J. C. Rolfe):

consecutusque cohortis ad Rubiconem flumen, qui prouinciae eius finis erat, paulum constitit, ac reputans quantum moliretur, conuersus ad proximos: ‘etiam nunc,’inquit, ‘regredi possumus; quod si ponticulum transierimus, omnia armis agenda erunt.’ cunctanti ostentum tale factum est. quidam eximia magnitudine et forma in proximo sedens repente apparuit harundine canens; ad quem audiendum cum praeter pastores plurimi etiam ex stationibus milites concurrissent interque eos et aeneatores, rapta ab uno tuba prosiliuit ad flumen et ingenti spiritu classicum exorsus pertendit ad alteram ripam. tunc Caesar: ‘eatur,’inquit, ‘quo deorum ostenta et inimicorum iniquitas uocat. iacta alea est,’ inquit.

Then, overtaking his cohorts at the river Rubicon, which was the boundary of his province, he paused for a while, and realising what a step he was taking, he turned to those about him and said: “Even yet we may draw back; but once cross yon little bridge, and the whole issue is with the sword.”  As he stood in doubt, this sign was given him. On a sudden there appeared hard by a being of wondrous stature and beauty, who sat and played upon a reed; and when not only the shepherds flocked to hear him, but many of the soldiers left their posts, and among them some of the trumpeters, the apparition snatched a trumpet from one of them, rushed to the river, and sounding the war-note with mighty blast, strode to the opposite bank. Then Caesar cried: “Take we the course which the signs of the gods and the false dealing of our foes point out. The die is cast,” said he.

A lot has been written about the crossing of the Rubicon and the phrase ‘the die is cast‘ (and its Greek origins). Equally, the role of visions, premonitions, dreams, and omens in Caesar’s life (right down to the point of his death) has been well-explored.

Moreover, historians such as Peter Wiseman (in Roman Drama and Roman History) and Gregor Weber (in Kaiser, Träume und Visionen in Prinzipat und Spätantike) have quite rightly pointed out that the introduction of this episode in Suetonius’ report may be testimony to an early dramatisation of this particular historical event for theatrical performance.

But what truly fascinates me about Suetonius’ report is something else. It is the role of music and sound as imagined in this report.

According to Suetonius, Caesar, his soldiers, and local shepherds encounter an apparition – an apparition that is described as of eximia magnitudine et forma, ‘of wondrous stature and beauty’. Sitting there, it played music upon a reed, harundine canens.

This creates an image of Pan, the god of shepherds, immersed in an idyllic, peaceful pastoral sphere and its archetypical music – the type that Vergil describes many a time in his Eclogues.

Illustration of the Roman Vergil. Image source (cropped) here.

Attracting shepherds and soldiers alike, the apparition then suddenly grabs the war-trumpet (tuba) of one of Caesar’s aeneatores, ‘trumpeters’, rushes down to the river bank, and sounds the charge: ingenti spiritu classicum exorsus pertendit ad alteram ripam, ‘and sounding the war-note with mighty blast, [he] strode to the opposite bank’.

Caesar, who had briefly hesitated to risk everything, according to Suetonius’ account interprets this as a sign from the gods and thus decides to go to war.

The change in tune is sudden and unexpected.

The peaceful, idyllic world of an idealised pastoral sphere with its gentle tunes played on a reed, attractive to shepherds and soldiers alike, is suddenly abandoned and replaced with the discordant tune of the war-trumpet, whose sound was famously described first by Ennius (reported e.g. at Serv. Aen. 9.501) –

at tuba terribili sonitu taratantara dixit

But the war-trumpet spoke ‘ta-ra-tan-ta-ra’ with its horrible noise

and subsequently, based on the Ennian model, by Vergil (Verg. Aen. 9.503–504) –

at tuba terribilem sonitum procul aere canoro
increpuit, sequitur clamor caelumque remugit.

But the war-trumpet, with its bronze gifted with song, widely
rattles its terrible sound, followed by a clamour, and the sky resounds.

Depiction of the tuba on Trajan’s column. – Image source here.

The change in tune from peaceful singing (canens) to the mighty blast of the trumpet (ingenti spiritu classicum exorsus), and the change of instrument from the reed (harundo) to the war-trumpet (tuba) both symbolise the imminent departure: a departure from a world in which soldiers and shepherds alike, for a short, fleeting moment, get to share the peace and joy of a pastoral idyll, towards an era of new war heralded by the harsh, terrible sound of the tuba, in which the sound of music cannot prevail (Verg. ecl. 9.1–13, translation from here):

Lycidas:
Where are you heading, Moeris? To town, where the path leads?

Moeris:
O Lycidas, we’ve lived to see the time when a stranger,
owner of our land, could say (as we never thought could happen):
‘These lands are mine: you old tenants move on.’
Now sad and defeated, since chance overturns all,
we send him these kids (may no good come of it).

Lycidas:
Surely I’d heard that your Menalcas, with his songs,
had rescued all your land, from where the hills end,
where they descend, in a gentle slope, to the water
and to the ancient beeches, with shattered tops?

Moeris:
You heard it, and that was the tale: but our songs
are as much use, Lycidas, among the clash of weapons,
as they say the Chaonian doves are when the eagle’s near.

For Caesar, according to Suetonius’ account, the transition from the sound of the harundo to that of the tuba were the ‘signs of the gods’, the deorum ostenta, that he craved to avenge the inimicorum iniquitas, the ‘false dealing of our foes’ (a double motivation worthy of Homeric epic!).

For me, given that the crossing of the Rubicon symbolises an irreversible step (which may or may not have been necessary), the more important question is this, however: how does one achieve the transition back from that horrible taratantara noise of the war-trumpet to that gentle, civilised, idyllic sound of the reed?