Over time , Nero became progressively more powerful , freeing himself of his advisers and eliminating rivals to the throne . In 55 , he removed Marcus Antonius Pallas , an ally of Agrippina , from his position in the treasury . Pallas , along with Burrus , was accused of conspiring against the Emperor to bring Faustus Sulla to the throne . Seneca was accused of having relations with Agrippina and embezzlement . Seneca succeeded in having himself , Pallas and Burrus acquitted . According to Cassius Dio , at this time , Seneca and Burrus reduced their role in governing from careful management to mere moderation of Nero .