For thousands of years, humans have been playing some type of sport that incorporates balls, whether it be for entertainment, religious ceremony or military training. It's not only interesting to look at how these sports were created, but how the balls themselves were designed and improved upon over thousands of years. People were basically using whatever was available around them, so some of the histories can be rather gruesome. From animal bladders to human heads and the skulls of your enemies, balls back then were a little different than they are today.