The Twelve Caesars by Suetonius (Penguin Classics)

Covering the Roman rulers from Julius Caesar to Domitian, this remains one of the richest and most fascinating of all Latin histories. Suetonius gathered much of his information from eye-witnesses, checking his facts carefully and quoting conflicting evidence without bias. But his history is also the most vivid and the raciest account we have of scandalous and amusing incidents in the domestic lives of the first Caesars.