When the Greeks assembled at Thermopylae1
learned that the army of the Gauls was already in the neighborhood of Magnesia
, they resolved to detach the cavalry and a thousand light armed troops and to send them to the Spercheius, so that even the crossing of the river could not be effected by the barbarians without a struggle and risks. On their arrival these forces broke down the bridges and by themselves encamped along the bank. But Brennus himself was not utterly stupid, nor inexperienced, for a barbarian, in devising tricks of strategy.