Antony's Campaign Against the Medes

36 BC

When Antony had done this and was awaiting the truce, the Medes burned his engines and scattered his mounds, and the Parthians made no proposition to him respecting peace, but suddenly attacked him and inflicted very serious injuries upon him. Learning, therefore, that he had been deceived, he did not venture to send any more envoys, as he did not expect that the barbarians would make peace on any reasonable terms and moreover did not wish to cast the soldiers into dejection by failing to arrange a truce, but he resolved, since he had once set out, to hurry on into Armenia. His troops took another road, since they believed the one by which they had come had been completely closed to them, and on the way they met with many extraordinary adventures. Thus, they came into unknown regions where they lost their way, and furthermore the barbarians seized the passes in advance of their approach, blocking them with trenches or palisades, rendered the securing of water difficult everywhere, and destroyed the pasturage; and in case they ever by good luck were on the point of marching through more favourable regions, the enemy would turn them aside from such places by false announcements that they had been occupied beforehand, and caused them to take different roads along which ambuscades had been previously posted, so that many perished in this way and many of hunger. As a result there were some desertions, and they would all have gone over to the enemy, had not the barbarians shot down before the eyes of the others any who had ventured to take this course. Consequently the men refrained from this, and by good fortune hit upon the following idea. One day, when they fell into an ambush and were being struck by dense showers of arrows, they suddenly formed the testudo by joining their shields, and rested their left knees on the ground. The barbarians, who had never seen anything of the kind before, thought that they had fallen from their wounds and needed only one finishing blow; so they threw aside their bows, leaped from their horses, and drawing their daggers, came up close to put an end to them. At this the Romans sprang to their feet, extended their battle-line at the word of command, and confronting the foe face to face, fell upon them, each one upon the man nearest him, and cut down great numbers, since they were contending in full armour against unprotected men, men prepared against men off their guard, heavy infantry against archers, Romans against barbarians. All the survivors immediately retired and no one followed them thereafter.

This testudo and the way in which it is formed are as follows. The baggage animals, the light-armed troops, and the cavalry are placed in the centre of the army. The heavy-armed troops who use the oblong, curved, and cylindrical shields are drawn up around the outside, making a rectangular figure; and, facing outward and holding their arms at the ready, they enclose the rest. The others, who have flat shields, form a compact body in the centre and raise their shields over the heads of all the others, so that nothing but shields can be seen in every part of the phalanx alike and all the men by the density of the formation are under shelter from missiles. Indeed, it is so marvellously strong that men can walk upon it, and whenever they come to a narrow ravine, even horses and vehicles can be driven over it. Such is the plan of this formation, and for this reason it has received the name testudo, with reference both to its strength and to the excellent shelter it affords. They use it in two ways; either they approach some fort to assault it, often even enabling men to scale the very walls, or sometimes, when they are surrounded by archers, they all crouch together-even the horses being taught to kneel or lie down-and thereby cause the foe to think that they are exhausted; then, when the enemy draws near, they suddenly rise and throw them into consternation.

The testudo, then, is the kind of device just described....

Dio's Roman History. (London: 1917), pp. 399-403.