8. AGRIPPINA THE YOUNGER
A feud between Agrippina the Younger and Nero forced the Roman Emperor to decide that his mother had to die. While he mulled over traditional methods of assassination, such as having her stabbed or poisoned by a trained killer, he eventually settled on a series of foolhardy plans to attempt to make the death appear as an accident.
According to contemporary sources, one of the first plots involved a specially made mechanical ceiling that was able to drop down and crush anyone caught underneath it. When this failed to work, Nero had a collapsible boat constructed that would sink when Agrippina was aboard. This also did not work as planned, as the woman swam to shore. Eventually, the emperor had to settle for paying a group of men to kill her and make it look like a suicide.