Titus Livius (Livy), The History of Rome, Book 41
Evan T. Sage, Ph.D. and Alfred C. Schlesinger, Ph.D., Ed.

2. The Histrians, as soon as the Romans had moved their camp to the lake of Timavus, themselves took up a hidden position in a spot behind a hill, and thence over byways followed the line of march, prepared for any opportunity; [2] nor did anything that took place on land or sea escape their observation. [3] [p. 189]When they saw that the outposts in front of the¹ camp were weak, and that the market, filled with an unarmed throng trafficking between the camp and the sea, was provided with no protection on land or on water, they at the same time attacked the two out-guards, the cohort from Placentia and the maniples of the second legion. [4] A morning fog had concealed their enterprise; and as this cleared away before the first warmth of the sun, the light now penetrating it to some extent, but as yet, as is usual, not clear and furnishing the beholder a magnified impression of everything, at this time also deceived the Romans and revealed to them a battle-line of the enemy far stronger than it really was. [5] When the soldiers from both outposts, terrified by this sight, had fled to the camp with mighty uproar they caused far more panic there than they had brought with them. [6] For they could neither explain from what they had fled nor answer any persons who questioned them; and some shouting at the gates was heard, showing that no guards were there to withstand an assault; and the rushing about in the dark, as one man collided with another, had made it uncertain whether or not the enemy was inside the rampart. [7] One voice was heard, that of men calling them to the sea; this cry, perhaps raised without design by a single man, rang everywhere through the whole camp. [8] And so a few at first, as if they had been ordered to do this, some armed, the majority unarmed, rushed down to the sea, then larger numbers, finally almost all of them, and even the consul, when, trying in vain to recall the fugitives, he had failed at the end to accomplish anything by orders or authority or entreaties. [9] One man alone remained, Marcus [p. 191]Licinius Strabo, military tribune of the third legion,² having along with three companies been left behind by his legion. The Histrians, bursting into the empty camp, when no other armed man had met them, bore down upon him at the headquarters as he was forming his men and encouraging them. [10] A battle began, fiercer than one would expect considering the small number of defenders, and did not stop until the tribune of the soldiers and the men who had made a stand with him had fallen. The enemy, tearing down the general's tent and plundering whatever was there, moved on to the quaestor's quarters, the market, and the via quintana.³ [11] When they had found there abundance of everything ready and laid out, [12??] and in the quaestor's quarters couches spread,⁴ the chief reclined and began to dine. [13] Presently all the others, forgetting their arms and the enemy, did the same; and since the rather rich fare was strange to them, they greedily loaded their bodies with wine and food.