[1] The affair thus ended, war was declared on the . . . ¹ and Lentienses, ² tribes of the Alamanni, who often made extensive inroads through the Roman frontier defences. On that expedition the emperor himself set out and came to Raetia and the Campi Canini; ³ and after long and careful deliberation it seemed both honorable and expedient that, while he waited there with a part of the soldiers, Arbetio, commander of the cavalry, with the stronger part of the army should march on, skirting the shores of Lake Brigantia, ⁴ in order to engage at once with the savages. Here I will describe the appearance of this place as briefly as my project allows.

[2] Between the defiles of lofty mountains the Rhine rises and pours with mighty current over high rocks, without receiving tributary streams, just as the Nile with headlong descent pours over the cataracts. And it could be navigated from its very source, since it overflows with waters of its own, did it not run along like a torrent rather than a quietly flowing river.

[3] And now rolling to level ground and cutting its way between high and widely separated banks, it enters a vast round lake, which its Raetian neighbour calls Brigantia; ⁵ this is four hundred and sixty stades long and in breadth spreads over an almost equal space; it is inaccessible through the bristling woods of the gloomy forest except where that old-time practical Roman ability, in spite of the opposition of the savages, the nature of the region, and the rigour of the climate, constructed a broad highroad.

[4] Into this pool, then, the river bursts roaring with frothing eddies, and cleaving the sluggish quiet of the waters, cuts through its midst as if with a boundary line. And as if the element were divided by an everlasting discord, without increasing or diminishing the volume which it carried in, it emerges with name and force unchanged, and without thereafter suffering any contact it mingles with Ocean’s flood.

[5] And what is exceeding strange, neither is the lake stirred by the swift passage of the waters nor is the hurrying river stayed by the foul mud of the lake, and though mingled they cannot be blended into one body; but if one’s very sight did not prove it to be so, one would not believe it possible for them to be kept apart by any power.

[6] In the same way the river Alpheus, rising in Arcadia and falling in love with the fountain Arethusa, cleaves the Ionian Sea, as the myth tells us, and hastens to the retreat ⁶ of the beloved nymph.

[7] Arbetio did not wait for the coming of messengers to announce the arrival of the savages, although he knew that a dangerous war was on foot, and when he was decoyed into a hidden ambuscade, he stood immovable, overwhelmed by the sudden mischance.

[8] For the enemy sprang unexpectedly out of their lurking-places and without sparing pierced with many kinds of weapons everything within reach; and in fact not one of our men could resist, nor could they hope for any other means of saving their lives than swift flight. Therefore the soldiers, bent on avoiding wounds, straggled here and there in disorderly march, exposing their backs to blows. Very many however, scattering by narrow by-paths and saved from danger by the protecting darkness of the night, when daylight returned recovered their strength and rejoined each his own company. In this mischance, so heavy and so unexpected, an excessive number of soldiers and ten tribunes were lost.

[9] As a result the Alamanni, elated in spirit, came on more boldly the following day against the Roman works; and while the morning mist obscured the light they rushed about with drawn swords, gnashing their teeth and giving vent to boastful threats. But the targeteers ⁷ suddenly sallied forth, and when they were driven back by the opposition of the enemy’s battalions, and were at a standstill, with one mind they called out all their comrades to the fight.

[10] But when the majority were terrified by the evidence of the recent disaster, and Arbetio hesitated, believing that the sequel would be dangerous, three tribunes sallied forth together: Arintheus, lieutenant-commander of the heavy-armed bodyguard, Seniauchus, leader of a squadron of the household cavalry, ⁸ and Bappo, an officer of the veterans. ⁹

[11] They with the soldiers under their command, devoting themselves on behalf of the common cause, like the Decii of old, ¹⁰ poured like a torrent upon the enemy, and not in a pitched battle, but in a series of swift skirmishes, put them all to most shameful flight. And as they scattered with broken ranks and encumbered by their haste to escape, they exposed themselves unprotected, and by many a thrust of swords and spears were cut to pieces.

[12] And many, as they lay there, slain horse and man together, seemed even then to be sitting fast upon the back of their mounts. On seeing this, all who had been in doubt about going into battle with their comrades poured forth from the camp, and careless of all precaution trod under foot the horde of savages, except those whom flight had saved from death, trampling on heaps of dead bodies and drenched with the blood of the slain.

[13] The battle thus done and ended, the emperor returned in triumph and joy to Milan, to pass the winter.