The Roman emperor Commodus wanted to kill a rhinoceros with a bow and arrow, and he wanted to do it in the Colosseum. Commodus's passion for hunting animals was so fervent that he dreamt of shooting a tiger, an elephant, and a hippopotamus; his prowess was such that people claimed he never missed when hurling his javelin or firing arrows from his bow. For fourteen days near the end of AD 192, the emperor mounted one of the most lavish and spectacular...