Plutarch Pompey 71

[1] So then, when the Pharsalian plain was filled with men and horses and arms and the signals for battle had been lifted on both sides, the first to rush out from Caesar’s lines was Caius Crassianus, ¹ a centurion in command of one hundred and twenty men, who was thus redeeming a great promise made to Caesar.

[2] For he had been the first man whom Caesar saw as he issued from the camp, and addressing him, he had asked him what be thought about the battle. The centurion stretched forth his right hand and cried with a loud voice: Thou wilt win a splendid victory, O Caesar; and I shall have thy praise to-day, whether I live or die. Mindful now of these words of his, he rushed forward, carrying many along with him, and threw himself into the midst of the enemy.

[3] The combatants at once took to their swords and many were slain, and as the centurion was forcing his way along and cutting down the men in the front ranks, one of them confronted him and drove his sword in at his mouth with such force that its point went through to the nape of his neck. ²
  After Crassianus had fallen, the battle was evenly contested at this point; Pompey, however, did not lead up his right wing swiftly, but kept looking anxiously towards the other parts of the field, and awaited the action of his cavalry on the left, thus losing time.

[4] These at last deployed their squadrons with a view to envelop Caesar, and to hurl back upon their supporting lines the horsemen whom he had stationed in front, only a few in number. But Caesar gave a signal, his cavalry retired, and the cohorts drawn up to oppose the enveloping movement ran out, three thousand men, and confronted their enemies, and standing close by the horses, as they had been directed, they thrust their javelins upwards, aiming at the faces of the riders.

[5] These, since they were without experience in every kind of fighting, and did not expect or even know anything about such a kind as this, had neither courage nor endurance to meet the blows which were aimed at their mouths and eyes, but wheeling about and putting their hands before their faces, they ingloriously took to flight. Then Caesar’s soldiers, suffering these to make their escape, advanced upon the enemy’s infantry, attacking at just that point where the wing, left unprotected by the flight of the cavalry, could be surrounded and enclosed.

[6] And since this body attacked them on the flank, while at the same time the tenth legion fell upon their front, the enemy did not stand their ground nor even hold together, for they saw that while they were expecting to surround the enemy, they were themselves being surrounded.