The Augustan History (Latin: Historia Augusta) is a late Roman collection of biographies, in Latin, of the Roman Emperors, their junior colleagues and usurpers of the period 117 to 284. It presents itself as a compilation of works by six different authors (collectively known as the Scriptores Historiae Augustae), written in the reigns of Diocletian and Constantine I, but the true authorship of the work, its actual date, and its purpose, have long been matters for controversy.