Testudo formation

In ancient Roman warfare, the testudo or tortoise formation was a type of shield wall formation commonly used by the Roman legions during battles, particularly when they were the attacking force during sieges. In the testudo formation, the soldiers would align their shields to form a packed formation covered with shields on the front and top. The first row of men, possibly excluding the men on the flanks, would hold their shields from about the height of their shins to their eyes, so as to cover the formation's front. The shields would be held in such a way that they presented a shield wall to all sides. The soldiers in the back ranks would place their shields over their heads to protect the formation from above, balancing the shields on their helmets, overlapping them. If necessary, the legionaries on the sides and rear of the formation could stand sideways or backwards with shields held as the front rows, so as to protect the formation's sides and rear; this reduced the speed and mobility of the formation, but offered consistent defensive strength against opposing infantry and excellent protection against arrows and other missile attacks. Plutarch describes this formation as used by Mark Antony during his invasion of Parthia in 36 BC: Then the shield-bearers wheeled round and enclosed the light-armed troops within their ranks, dropped down to one knee, and held their shields out as a defensive barrier. The men behind them held their shields over the heads of the first rank, while the third rank did the same for the second rank. The resulting shape, which is a remarkable sight, looks very like a roof, and is the surest protection against arrows, which just glance off it. Cassius Dio writes about the testudo when describing the campaign of Mark Antony in 36 BC: This testudo and the way in which it is formed are as follows.