Apollonius of Tyana (15-100 AD) was a Greek Neopythagorean philosopher. The most detailed source is the Life of Apollonius of Tyana, a novelistic biography written by the sophist Philostratus. One of the essential sources Philostratus claimed to know are the diary of Damis, an acolyte and companion of Apollonius. Philostratus describes Apollonius as a wandering teacher of philosophy and miracle worker who was mainly active in Greece and Asia Minor but also traveled to Italy, Spain and North Africa and even to Mesopotamia, India, and Ethiopia. He tells lengthy stories of Apollonius entering the city of Rome in disregard of Emperor Nero's ban on philosophers, and later on being summoned to the court of Domitian, where he defied the Emperor. He had allegedly been accused of conspiring against the Emperor, performing human sacrifice, and predicting a plague by means of magic. Philostratus implies that upon his death, Apollonius of Tyana underwent heavenly assumption. Engraving by J.W. Cook, 1825.