Every second Saturday of the month, the Science Center here does a theme. Last month it was "Roman Day". They had several artifacts from the Romans including these high pressured catapults. They would shoot arrows at the enemies for miles around.
An old Roman pulley system
Then several re-enacted a Roman army march and call to battle
The shields were so heavy that when in battle, if their swords didn't kill the enemy, they could push the shield down on the enemy's foot, potentially cutting off his foot to wound him.
Marching to battle forming a human shield. A lot was learned that day! Even relates to biblical times.