Apollonius of Tyana (ca. 40-120 AD) was a Greek Pythagorean philosopher and teacher. He hailed from the town of Tyana in the Roman province of Cappadocia in Asia Minor. His date of birth is a matter of conjecture as some say he was roughly a contemporary of Jesus.

After Apollonius' death his name remained famous among philosophers and occultists. In a "novelistic invention" inserted in the Historia Augusta, Aurelian, at the siege of Tyana in 272, was said to have experienced a visionary dream in which Aurelian claimed to have seen Apollonius speak to him, beseeching him to spare the city of his birth. In part, Aurelian said that Apollonius told him "Aurelian, if you desire to rule, abstain from the blood of the innocent! Aurelian, if you will conquer, be merciful!"

By far the most detailed source is the Life of Apollonius of Tyana, a lengthy, novelistic biography written by the sophist Philostratus at the request of empress Julia Domna. Philostratus’ account shaped the image of Apollonius for posterity and still dominates discussions about him in our times. To some extent it is a valuable source because it contains data from older writings which were available to Philostratus but disappeared later on. Many think that it is full of obviously fictitious stories and dialogues. Modern Christian scholars challenge its credibility in many regards. They dismiss most of it as pure invention.

One of the essential sources Philostratus claimed to know are the memoirs or diary of Damis, an alleged disciple and companion of Apollonius. Some scholars believe the notebooks of Damis are an invention of Philostratus. In any case it is a literary fake. Philostratus describes Apollonius as a wandering teacher of philosophy and miracle worker who was active in Italy, Spain and Ethiopia and even travelled to Mesopotamia, Arabia and India. In particular, 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, as a defendant to the court of emperor Domitian where he defied the emperor in blunt terms.

Apollonius may have never left the Greek East. Many contend that he never came to Western Europe and was virtually unknown there till the third century AD when empress Julia Domna, who was herself an Easterner, decided to popularize him and his teachings in Rome. For that purpose she commissioned Philostratus to write the biography, where Apollonius is exalted as a fearless sage with supernatural powers, even greater than Pythagoras. Philostratus implies that upon his death, Apollonius of Tyana underwent heavenly assumption. Subsequently Apollonius was worshipped by Julia’s son emperor Caracalla and possibly also by her grand-nephew emperor Severus Alexander.

Two biographical sources earlier than Philostratus are lost: a book by emperor Hadrian’s secretary Maximus of Aegae describing Apollonius’ activities in the city of Aegae in Cilicia, and a biography by a certain Moiragenes. (Summary adapted from Wikipedia by Karen Merline)