Julio-Claudian dynasty reign as being strongly influenced by his mother Agrippina, his tutor Seneca, and the Praetorian Prefect Burrus, especially in the first year. He was made Emperor over his step-brother, Claudius' son Britannicus, who he had killed. Agrippina was believed to have poisoned Claudius, having allegedly poisoned her second husband Gaius Sallustius Crispus Passienus. She had also arranged the deaths of Caligula's third wife, Lollia Paulina and Messalina's mother Domitia Lepida the Younger. She saw that the dynasty's numbers dwindle with the execution of Marcus Junius Silanus Torquatus, a grandson of Julia the Younger, to strengthen Nero's claim, having previously arranged
Agrippina the Elder the emperor, which would have made him a member of the imperial family. While this did make his ambitions clear, his request was denied. The loss may have been huge for Sejanus had the dissensions in the imperial household not been deteriorating. Relations were so bad that Agrippina refused to eat at Tiberius' dinner parties for fear of being poisoned. She also asked Tiberius if she could be allowed to remarry, which he also refused. If either of them were allowed to remarry it would have threatened the line of succession that Tiberius was comfortable with. By refusing Sejanus' request,