Agrippina the Younger and stepfather in 50. Lucius' name was changed to "Nero Claudius Caesar Drusus Germanicus" and he became Claudius's adopted son, heir and recognised successor. Agrippina and Claudius betrothed Nero to Octavia, and Agrippina arranged to have Seneca the Younger return from exile to tutor the future emperor. Claudius chose to adopt Nero because of his Julian and Claudian lineage. Agrippina deprived Britannicus of his heritage and further isolated him from his father and succession for the throne in every way possible. For instance, in 51, Agrippina ordered the execution of Britannicus' tutor Sosibius because he had confronted her and was
Claudia Acte became emperor in 54 AD, after his great-uncle/stepfather died—apparently poisoned, in the belief of contemporary historians, by his niece/wife, Agrippina, Nero's mother. A year into Nero's reign, encouraged by Seneca the Younger and Burrus, and against Agrippina the Younger's wishes, Nero took Acte as his mistress. Seneca especially was concerned that his young student would not be satisfied with his wife, Octavia, and might indulge in risky sexual exploits. This made Acte appear a safe outlet and a source of separation from Agrippina. Seneca and Burrus were on uneasy terms with Agrippina and were nervous about her political influence and