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
Vipsania Marcella Vipsania Marcella Vipsania Marcella Agrippina or Marcellina or Vipsania Tertia (born 27 BC or later) was perhaps the only daughter of Roman statesman Marcus Vipsanius Agrippa by his second wife Claudia Marcella Major. If so, she was the first grandchild to Octavia Minor and first great-niece to Roman Emperor Augustus. If she truly had the name Marcella, there is no way that she was a daughter of Agrippa's first wife, Caecilia Attica. She and her elder sister Vipsania Agrippina were married off to Quintus Haterius (cos. 5 BC), Publius Quinctilius Varus (cos. 13 BC) and Tiberius (also cos. 13 BC)