A felled tree trunk typically served as a battering ram during Medieval times. A battering ram's purpose was to open heavy doors using the force of the ram. Men would repeatedly force the battering ram at the door until the strength of the motion pushed the door open or broke it into pieces. Since the battering ram could be constructed using relatively few materials, it became a popular weapon for the Medieval soldiers. Eventually, it became reinforced with steel at the top. Later, four sides were constructed around the ram to protect the men who were using it from attack.
Fill the cardboard tube with rolled up pieces of cardboard, until the tube feels solid and you cannot bend it.
Use two strips of duct tape to tape over the ends of the tube to prevent the paper from falling out.
Wrap duct tape around the entire tube. Start at the one end of the tube and carefully, wrap the duct tape around the tube until you have reached the top.
Make a model of a ram's head to stick at the top of the battering ram. This was done in later Medieval times. Use a small milk container to construct the head. Paint the carton white and cut a circular hole in the bottom of it. Place the battering ram inside the hole. Duct tape around it. Add eyes to either side of the milk carton opening and add horns made from cardboard to the top of the carton.