Complex sentence: In 49, Claudius'fourth wife Agrippina the Younger had Seneca recalled to Rome to tutor her son Nero, then 12 years old; on Claudius' death in 54, she secured recognition of Nero, rather than Claudius' son Britannicus, as emperor.
Split into simpler sentences: In 49, Claudius'fourth wife Agrippina the Younger had Seneca recalled to Rome to tutor her son Nero, then 12 years old. On Claudius' death in 54, she secured recognition of Nero, rather than Claudius' son Britannicus, as emperor.