Plutarch Caesar 24

[1] Caesar’s forces were now so large that he was forced to distribute them in many winter-quarters, while he himself, as his custom was, turned his steps towards Italy. Then all Gaul once more broke out in revolt, ¹ and great armies went about attacking the entrenchments and trying to destroy the winter-quarters of the Romans. The most numerous and powerful of the rebels, under Abriorix, ² utterly destroyed Titurius and Cotta, together with their army,

[2] while the legion under Cicero was surrounded and besieged by sixty thousand of them, and narrowly escaped having its camp taken by storm, although all were wounded and went beyond their powers in the ardour of their defence..
  When tidings of these things reached Caesar, who was far on his journey, he turned back quickly, got together seven thousand men in all, and hurried on to extricate Cicero from the siege. But the besiegers became aware of his approach, and went to meet him with the purpose of cutting his forces off at once, despising their small numbers.

[3] Caesar deceived them by avoiding battle continually, and when he had found a place suitable for one who was fighting against many with few, fortified a camp, where he kept his men altogether from fighting and forced them to increase the height of their ramparts and the defences of their gates as though they were afraid. His strategy thus led the enemy to despise him, until at last, when their boldness led them to attack in scattered bands, he sallied out, routed them, and destroyed many of them.