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 still survives (). Agrippina was fiercely independent, a trait she shared with her mother. Dio described her as having ambitions to match her pedigree. However, Anthony Barrett notes that Agrippina was fully aware that a woman in ancient Rome could not hold power in her own right. Instead, Agrippina followed the model of Livia in promoting the careers of her children. She and her daughter, Agrippina the Younger, are both described as being equally ambitious for their sons. Whereas the elder Agrippina's son failed to become emperor, the younger Agrippina's son, also named Nero, succeeds. In a contrast, Tacitus has