Contrary to the usual strict principles of Roman discipline, Varus had suffered his army to be accompanied and impeded by an immense train of baggage-waggons, and by a rabble of camp followers; as if his troops had been merely changing their quarters in a friendly country. When the long array quitted the firm level ground, and began to wind its way among the woods, the marshes, and the ravines, the difficulties of the march, even without the intervention of an armed foe, became fearfully apparent. In many places the soil, sodden with rain, was impracticable for cavalry and even for infantry, until trees had been felled, and a rude causeway formed through the morass.
The duties of the engineer were familiar to all who served in the Roman armies. But the crowd and confusion of the columns embarrassed the working parties of the soldiery, and in the midst of their toil and disorder the word was suddenly passed through their ranks that the rear-guard was attacked by the barbarians. Varus resolved on pressing forward; but a heavy discharge of missiles from the woods on either flank taught him how serious was the peril, and he saw the best men falling round him without the opportunity of retaliation; for his light-armed auxiliaries, who were principally of Germanic race, now rapidly deserted, and it was impossible to deploy the legionaries on such broken ground for a charge against the enemy. Choosing one of the most open and firm spots which they could force their way to, the Romans halted for the night; and, faithful to their national discipline and tactics, formed their camp amid the harassing attacks of the rapidly thronging foes, with the elaborate toil and systematic skill, the traces of which are impressed permanently on the soil of so many European countries, attesting the presence in the olden time of the imperial eagles.