Caracalla's real name was Marcus Aurelius Antoninus. He got the nickname from his habit of wearing a cloak by the same name. Caracalla was the elder son of Septimius Severus and brother of Geta whom he positively hated. Hated so much, in fact, that he had him murdered a few years later. In the mayhem that followed, Caracalla's men went on a killing spree of anyone suspected of being a Geta sympathizer. In the massacre, it's estimated up to 20,000 people lost their lives. Caracalla would go on to rule for another five years but his bad karma caught up with him and he was assassinated in a plot perpetrated by Macrinus.
As an emperor Caracalla possessed few redeeming qualities and among the worst of them would be his ruinous drain on the treasury. Because he knew everyone hated him he sought the protection of the army. And the surest way of getting this protection was to buy it outright. He raised the pay of the solider to about four denarii per day, nearly quadrupling the salary of just a few years prior. And on top of their regular salary he heaped endless bonuses and other concessions meant to endear them. This money could only have come by the oppressive taxation of ordinary citizens as well as the seizures of property of the wealthy under trumped-up charges. This not only intensified the hatred against him but also had the effect of corrupting the military who had become accustomed to this life of luxury and throwing the economy into lasting disarray.