Tiberius Claudius Drusus Nero Germanicus n 1: Roman Emperor after his nephew Caligula was murdered; consolidated the Roman Empire and conquered southern Britain; was poisoned by his fourth wife Agrippina after her son Nero was named as Claudius' heir (10 BC to AD 54) [syn: {Claudius}, {Claudius I}, {Tiberius Claudius Drusus Nero Germanicus}]