Anonymus Valesianus I, also called Origo Constantini talks about the life of Constantine the Great, roughly the time of 301 to 337 AD. The author is unknown, and was probably pagan. Most likely the text was written shortly after the death of the emperor. The author gives a good review of the life, and offers details which can be found in no other text. The text was written around 390, and is regarded as a reliable source