Second Roman emperor (A.D. 14-A.D. 37). He was the son of Tiberius Claudius Nero and Livia Drusilla and was originally named Tiberius Claudius Nero. He campaigned (20 B.C.) in Armenia, became (19 B.C.) governor of Transalpine Gaul, and aided (12 B.C.) his brother Drusus on the Rhine and the Danube. Augustus, his stepfather, compelled him (12 B.C.) to divorce his wife, Vipsania Agrippina, and to marry Julia, the widow of Agrippa and daughter of Augustus. After the death of Drusus (9 B.C.) he campaigned in Germany, and following a second consulship (7 B.C.) he retired to Rhodes for seven years. On his return he was adopted as heir of the emperor and was sent (A.D. 4) into Germany. Five years later he subjugated Illyricum.
Tiberius succeeded without difficulty on the death of Augustus in A.D. 14. He spent his efforts in continuing the policies of Augustus, with one exception; he drastically cut luxury expenses, including public shows. By so doing and by reforming the tax situation in the provinces he greatly improved the financial state of the government and made himself extremely unpopular in Rome. For years Sejanus was his chief aid and confidant.
Tiberius retired to Capri in A.D. 26 and ruled thereafter by correspondence. He grew suspicious of intrigues and in A.D. 31 had Sejanus killed. Modern historians have been inclined to treat his administration more favorably than did Roman historians. He was succeeded by Caligula.
See studies by F. B. Marsh (1931) and Robin Seager (1972).