Testudo

The Testudo was an effective formation used by the Romans to protect their attacking groups of Legionnaires. Testudo is the Latin word for "tortoise". Groups of advancing Infantry formed a Testudo by holding their shields overhead, supported by their helmets, and interlocking them to protect against attack from above. If needed, a similar arrangement was organised along the front and sides.

The Testudo formation was effective at facing off archers for example, or to protect troops during Sieges as they scaled walls, but was slow moving and restricting so the Legionnaires would be ordered into another formation for close combat.

Overall, the term Testudo was given generally protective shelters under which Legionaires could approach the walls of a besieged fortification to mine under its walls or deploy a Battering Ram for example. The Musculus (small mouse) was similar but smaller.

The Romans often attacked fortifications not only by scaling their walls but also built ramps up to them. Light weight portable shelters known as Vineae (derived from 'Vines' and meaning a moveable bower or Pergola used as a shelter) were woven from Wicker, for example, and joined end to end to form a protective corridor for those building the ramps.

They also built larger portable shields or Mantlets to protect those at the front. Larger versions of Vineae were built known as Pluteus (meaning shed from its shape) and these too were used to get near to enemy walls. Often they were on three wheels to make them more manouvreable.