testudo formation
An army formation used by ancient Romans, meaning "tortoise" in classic Latin. The men in the front would hold their shields forward while the others would hold theirs facing upward, allowing the squad to advance forward while being protected from both frontal attacks as well as ranged attacks from archers and slingers. Sometimes, the squad would also have shieldbearers arranged to also protect the sides and rear as well, at the cost of forward mobility.