A trebuchet is a type of siege engine that uses counterweights to throw projectiles over long distances. They first appeared during the 4th century B.C.E. in China, and they were a powerful weapon for siege warfare. What was once popular on medieval battlefields is now popular on the subreddit /r/trebuchetmemes. Even thousands of years later, people still love this humble machine enough to share memes about it around the web.