"The Lives of the Twelve Caesars, Volume 05: Claudius" by Suetonius is a biography written in 121 CE as part of a larger work covering Julius Caesar and the first eleven Roman emperors. This volume focuses on Claudius, providing intimate details about his heritage, personal habits, physical appearance, and political career. Written while Suetonius served as personal secretary to Emperor Hadrian, the biography relies partly on secondhand accounts after the author lost access to official archives. Despite criticisms of sensationalism and bias, it remains a major primary source for understanding this enigmatic emperor's life and reign. (This is an automatically generated summary.)