And so conditions grew worse as the centuries went by. The first Emperors had continued the tradition of "leadership" which had given the old tribal chieftains such a hold upon their subjects. But the Emperors of the second and third centuries were Barrack-Emperors, professional soldiers, who existed by the grace of their body-guards, the so-called Praetorians. They succeeded each other with terrifying rapidity, murdering their way into the palace and being murdered out of it as soon as their successors had become rich enough to bribe the guards into a new rebellion.