Caligula

If you want to read about one of the "baddies," that is, one of the most deranged leaders in the history of History, you'll enjoy this one. Not much is known about Caligula, but it is established that his father, Germanicus, was a brilliant military leader, love throughout Rome. He was so loved that Tiberius, the emperor, adopted him with intentions of having a successor. When Germanicus dies Caligula becomes emperor.
Suetonius mentions that Caligula married his own sister, threatened to make his horse consul, and according to one rumor said he had his soldiers pick sea shells on their way to invade Britain (clearly the man was nuts). He would have people assassinated randomly, and then call for them. When they failed to appear he said they must have committed suicide. Eventually Caligula would be assassinated at a Gladiatorial event by a disgruntled guard, but not after earning a reputation as one of the maddest of Caesars ever to rule.