Original: Livy's History of Rome: Book 9 Biography, although popular throughout antiquity, was introduced as a branch of history by the works of Plutarch (c. 46 - 127) and Suetonius (c. 69-after 130) who described the deeds and characters of ancient personalities, stressing their human side.
Simplified: Livy's History of Rome: Book 9 Plutarch (c. 46 - 127) and Suetonius (c. 69-after 130) introduced biography as a branch of history.