Gaius Suetonius Tranquillus (c. 69-after 122 CE) was a Roman biographer and imperial secretary under Trajan and Hadrian. He wrote works on literature, grammar and public life, but is best known for The Twelve Caesars. His biographies combine archival detail, anecdote, scandal and character sketch rather than continuous political history.
The Twelve Caesars offers biographies of Julius Caesar and the first eleven Roman emperors from Augustus through Domitian. Suetonius does not write history as Tacitus does, with sustained analysis of institutions and causation.