Roman historians like Livy, Tacitus, Suetonius or Cassius Dio bear a special responsibility for modern readers. So many of the manuscript sources on which they based their writings have disappeared that we have to use them, in effect, as primary sources for the periods they wrote about, cross referencing where possible with other sources, literary or archaeological, or with what we know of other, analogous periods of history.

This is problematic because Roman historians were not writing for generations many centuries later but for the readers of their own day. Like other writings at the time, Roman historical works were often read aloud to an audience, so that writers often wrote with an ear to how their words would sound to a listener.

Suetonius The Twelve Caesars >>
Gibbon The Decline and Fall of the Roman Empire >>