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
Agrippina the Elder was made "princeps". While Germanicus was administering the oath of fealty to Tiberius, a mutiny began among the forces on the Rhine. During the mutiny, Agrippina brought out their sixth child, Gaius, and made preparations to take him away to a safer town nearby. He was in a full army outfit including the legionary hobnailed boots ("caligae"). These military-booties earned Gaius the nickname "Caligula" (lit. "little boots"), and garnered sympathy for Agrippina and the child among the soldiery. Tacitus attributes her actions as having quelled the mutiny (Tacitus, "Annals" 1.40–4). Once the mutiny was put to an end, Germanicus allowed