Julian was a member of the Constantinian dynasty and a descendant of Constantine the Great. He was one of the few male members of his family who survived a massacre that was ordered by Constantinus III. Later while still a young man he was promoted to the rank of Caesar. In 355 AD he inflicted a series of defeats on Alamanni and Franks, who had invaded Gaul. His greatest victory was over a great confederation of German tribes in 357 A.D. at the Battle of Argentoratum. He later after the death of Constantius III became the sole emperor of the Roman Empire. Unlike the other members of the Constantinian dynasty, he was a pagan. Julian was a philosopher, and under the influence of Neo-Platonist philosophy, he began to revere the Olympian Gods. He was brought up a Christian, but he believed came to believe that this religion was undermining the traditional Roman values’, and this was weakening the Empire <ref> Grant, Michael. The Roman Emperors (New York: Barnes and Noble Books, 1997), p. 254 </ref>. After assuming the purple, he marginalized the Christian Church and favored pagans, for example he restored many temples. Julian was careful not to persecute the Christians as he knew that previous persecutions had only strengthened that religion. The Christians hated him. Julian championed the ancient religion of Rome and Greece in a series of polemics. In his polemic 'Against the Galileans', he claims Christianity was a series of falsehoods. In one section of the work he stated ‘’ I was convinced that the fabrication of the Christians is a fiction of men composed by wickedness’ <ref> Julian, "Against the Galileans", 143</ref>. There is some evidence that his efforts to promote paganism did have some impact. The Emperor also favored the Jews. However, the Christians remained as powerful as ever, despite the change in Imperial policy. Some argue that Julian did not want to destroy Christianity but wanted ultimately to see the fusion of the Christian faith with the pagan polytheistic religion. Julian was a great administrator and he reformed the court, bureaucracy and granted more powers and privileges to the cities<ref> Grant, p. 255</ref>. In 363 AD the Emperor decided to launch a massive invasion of Persia. Many argue that there were sound strategic reasons for the proposed invasion. Persia under the Sassanian dynasty was a powerful enemy and had secured the strategic initiative on Rome’s Eastern Frontier. The pagan sources such as Ammianus, state that Julian invaded Persia to conquer the Persian Empire<ref> Ammianus, Histories, v.11</ref>. It is almost certain that Julian wanted to occupy large parts of Persia or to turn it into a puppet regime, as he brought a claimant to the Sassanian throne with him during his invasion. Another motive for Julian’s invasion was to emulate the achievement of Alexander the Great. The Emperor's main goal was to re-establish the old Graeco-Roman polytheistic religion. Julian’s invasion of the Persian territories could be interpreted as an attempt to secure a victory that would persuade the Romans’ to return to their old gods and abandon Christianity.
[[File: Julian two.jpg|200px|thumb|left|The acclamation of Julian as Caesar in Paris]]