Since Claudius was the first emperor proclaimed on the initiative of the Praetorian Guard instead of the Senate, his repute suffered at the hands of commentators (such as Seneca). Moreover, he was the first emperor who resorted to bribery as a means to secure army loyalty and rewarded the soldiers of the Praetorian Guard that had elevated him with 15,000 sesterces.

Political role

The Praetorian Guard influenced and intervened in the imperial succession to name the new Caesar, which was a political decision that the unarmed Senate accepted, ratified, and proclaimed to the people of Rome. After the death of Sejanus, who was sacrificed for the donativum (imperial gift) promised by Tiberius, the Praetorians became exceptionally ambitious in their influence upon the politics of the Roman Empire. Either by volition or for a price, the Praetorian Guard would assassinate an emperor, bully the Praetorian prefects, or attack the Roman populace. In AD 41, conspirators from the senatorial class and from the Guard killed Emperor Caligula, his wife, and their daughter. Afterwards, the Praetorians installed Caligula's uncle Claudius upon the imperial throne of Rome, and challenged the Senate to oppose the Praetorian decision.

In AD 69, the Year of the Four Emperors, after assassinating the Emperor Galba, because he did not offer them a donatium, the Praetorians gave their allegiance to Otho, whom they named as the new Caesar of Rome. To ensure the loyalty of the Praetorian Guard, Emperor Otho granted the Praetorians the right to appoint their own prefects. After defeating Otho, Vitellius disbanded the Praetorians and established a new Guard composed of sixteen cohorts. In his war against Vitellius, Vespasian relied upon the disgruntled cohorts dismissed by Emperor Vitellius, and, as Emperor Vespasian, he reduced the Praetorian Guard to nine cohorts and ensured their political loyalty by appointing his son, Titus, as prefect of the Praetorians.[7]