Battering Ram, a device for knocking down the walls of cities or other fortified places. It was invented by the Assyrians, and was in common use from Biblical times until the invention of cannon in the 14th century. In its simplest form the battering ram was a heavy wooden beam held parallel to the ground at shoulder height by a number of men on each side. The men would run a few steps with it to gain momentum, then crash its end against a door or wall. The forward end of a large battering ram was often covered with iron shaped like a ram's head, hence the name.
The largest rams resembled modern telephone poles and were so heavy they had to be suspended by ropes or chains from overhead frames. The frame was covered with a roof to protect the operators from stones or spears thrown from the wall above. The whole assembly was rolled near the enemy's wall or gate. The huge ram was then swung back and forth to beat against the wall. The force of such a ram was so great that no wall could long withstand its battering.