Plutarch Sertorius 18

[1] Well, then, as long as he carried on the war with Metellus as his antagonist, he was thought to be successful for the most part because, owing to great age and natural slowness, Metellus could not cope with a man who was bold and headed a force composed of robbers rather than soldiers; but when Pompey also crossed the Pyrenees and became his antagonist, ¹ and each of them had offered and accepted every test of a general’s powers, and Sertorius had the advantage in counter-planning and watchfulness, then indeed it was noised abroad as far as Rome that he was the ablest general of his time in the conduct of a war.

[2] For the fame of Pompey was by no means inconsiderable, nay, at this time his reputation was in most vigorous flower in consequence of the valiant deeds which he performed in the cause of Sulla, deeds for which he was given the surname of Magnus (that is, Great) by Sulla, and received the honours of a triumph while he was still beardless. Therefore, too, many of the cities which were subject to Sertorius turned their eyes towards Pompey and felt inclined to change their allegiance; they ceased to do this, however, after the disaster at Lauron, which happened contrary to all expectation.

[3]
  For Sertorius was besieging that city, and Pompey came to its assistance with all his forces. Now there was a hill which was thought to afford a good command of the city, and this hill Sertorius strove to seize in advance, while Pompey sought to prevent him. But Sertorius got there first, whereupon Pompey, taking position with his army, was delighted with the way things had turned out, believing that Sertorius was caught between the city and his adversary’s forces; he also sent a messenger in to the people of Lauron bidding them be of good cheer and take seats along their walls for the spectacle of Sertorius undergoing siege.

[4] When Sertorius heard of this, he gave a laugh, and said that to Sulla’s pupil (for thus he was wont to style Pompey in jest) he himself would give a lesson, namely, that a general must look behind him rather than in front of him. As he said this, he pointed out to his beleaguered troops six thousand men-at-arms whom he had left behind at their former camp, from which he had sallied forth to seize the hill; these, in case Pompey moved against the occupants of the hill, were to fall upon his rear.

[5] Pompey also became aware of this all too late, and did not venture to attack Sertorius for fear of being surrounded, but line was ashamed to go away and leave the people of the city in their peril, and so was compelled to sit there quietly and see them ruined; for the Barbarians gave up all hope and surrendered to Sertorius.

[6] Sertorius spared their lives and let them all go, but he burned down their city, ² not because he was angry or cruel, for he appears to have given way to passion less than any other general, but to put to shame and confusion the admirers of Pompey, in order that it might be said among the Barbarians that though he was near at hand and all but warming himself at the flames of an allied city, he did not come to its relief.