son. Claudius was convinced to do as Augustus had done in adopting Gaius and Lucius Caesar, and as Tiberius had done in adopting Germanicus despite having a son already. It was in February 50 that his father passed a law adopting Domitius into the Claudii and naming him Nero, and Domitius became "Nero Claudius Caesar". Nero and Britannicus then became joint-heirs to the emperor, and Agrippina was then given the honorable and high-ranking title of Augusta. In AD 51, his brother Nero assumed the toga virilis despite not yet being 14. The Senate also decided then that Nero should hold the consulship during his twentieth year (AD 56) and, as consul-elect, that he should enjoy imperium proconsulare ("proconsular authority") beyond the limits of Rome with the title of princeps iuventutis ("prince of the youth of Rome"). The progress of Nero seems to have followed in the footsteps of Gaius and Lucius Caesar. To mark the occasion, a donative was given to the soldiery of Rome, and presents to the people. His step-brother's status, along with that of Agrippina, is echoed on contemporary coinage. By contrast, Britannicus was progressively isolated. At the games of the circus Nero appeared in triumphal robes while Britannicus was still dressed as a boy. Tacitus says their clothing at the games affected the expectations of the people: with Nero in a general's clothing, and Britannicus in the dress of boyhood. He was not due for the toga until 12 February AD 55. He and his supporters were seen as a potential problem for Nero. Agrippina replaced his tutors with her own nominees, having convinced Claudius to order their executions, including the execution of Sosibius. Not just his tutors, but the two prefects of the Praetorian Guard, Lusius Geta and Rufius Crispinus, were replaced as well. They were thought to be sympathetic to the cause of Britannicus and his mother, as Tacitus reports: it would have been risky to surround Nero with any but those loyal to Claudius and Agrippina. His step-mother had them replaced with Sextus Afranius Burrus who was a good soldier, but knew to whom he owed his allegiance. Nero's career progressed steadily: he gave speeches in AD 51 and 52. The speech in 51 thanked the emperor for honours given to him, and that of 52 was a vow for the safe recovery of the emperor from illness. It was in 53 that