Agrippina the Younger outraged by Claudius' adoption of Nero and his choice of Nero as successor, instead of choosing his own son Britannicus. Nero and Octavia were married on June 9, 53. Claudius later repented of marrying Agrippina and adopting Nero, began to favor Britannicus, and started preparing him for the throne. His actions allegedly gave Agrippina a motive to eliminate Claudius. The ancient sources say she poisoned Claudius on October 13, 54 with a plate of deadly mushrooms at a banquet, thus enabling Nero to quickly take the throne as emperor. Accounts vary wildly with regard to this private incident and according
Agrippina the Elder ties to the emperor. Historian Richard Alston says it is likely that either Tiberius or Livia were behind the exile of Agrippina's half-sister and the death of Postumus. He notes the death of Agrippina's mother, who starved herself to death amidst her exile in AD 14, linking her death to Tiberius' disdain for her. Agrippina was vocal about her feelings claiming that Germanicus was murdered to promote Drusus the Younger as Tiberius' heir, and worried that the birth of the Younger Drusus' twin sons would displace her own sons in the line of succession. Her fears proved to be unfounded,