Infopedia: Claudius I. Full name Tiberius Claudius Drusus Nero Germanicus. 10 B.C.-54 A.D. Emperor (41-54 A.D.). Second son of Drusus (Nero Claudius Drusus), nephew of Tiberius, and stepgrandson of Augustus; neglected by Augustus and Tiberius. Proclaimed emperor by soldiers on death of Caligula. Married four times; third wife, at the time of his accession, Valeria Messalina; fourth wife (m. 49 A.D.), his niece Agrippina ( q.v. ), prevailed upon him to set aside his own son Britannicus and adopt her son Nero as heir. Carried on wars in Britain, Germany, Syria, and Mauretania; made the last a province (42 A.D.); also annexed Lycia (43), Thrace (46); founded city of Cologne (orig. Colonia Agrippinensis, 51); built Ostia harbor at mouth of Tiber, and the Claudian aqueduct. Poisoned by Agrippina.