Neoplatonism began to be adopted by prominent scholars such as the Christian theologian Origen and the anti-Christian Porphyry. During the rule of Gallienus, the imperial family themselves gave patronage to Plotinus, and encouraged his philosophical activities. Neoplatonism was further developed by Iamblichus, who believed that physical invocations would be able to produce soteriological results, and therefore added religious ritual to the philosophy. Emperor Julian tried to unify traditional Roman religion by mixing it with Iamblichus' form of neoplatonism; the influential Christian thinker Augustine of Hippo lived during this period, and his subsequent writings show heavy neoplatonic influence. At some time around the first century, the members of the Roman military began to adopt the mystery cult of Mithraism; this sun-god related cult arose from obscure non-Roman origins, and the first surviving reference dates to Plutarch's mention of a 67 BC observation of certain Mediterranean pirates practising it. As the Roman legions gradually moved around, so too Mithraism spread throughout the Roman Empire; in the beginning it was mainly soldiers who followed its precepts, but it was also adopted by freedmen, slaves, and merchants, in the locations where the legions rested, particularly in frontier areas. Mithraism wasn't exclusive - it was possible and common to follow Mithraism and other cults simultaneously. It eventually became popular within Rome itself, gradually gaining members among the more aristocratic classes, and eventually counting some of the Roman senators as adherents; according to the Augustan History, even the emperor Commodus was a member. Although, for reasons currently unknown, Mithraism completely excluded women, by the third century it had gained a wide following; there are over 100 surviving remains of temples to Mithras, 8 in Rome itself, and 18 in Ostia (Rome's main port), with Rome having over 300 associated Mithraic monuments. From the reign of Septimius Severus, other, less gender-specific, forms of sun-worship also increased in popularity throughout the Roman Empire. Elagabalus used his authority to install El-Gabal as the chief deity of the Roman pantheon, merging the god with the Roman sun gods to form "Deus Sol Invictus", meaning "God - the Undefeated Sun", and making him superior to Jupiter, and assigning either Astarte, Minerva, Urania, or some combination of the three, as El-Gabal's wife.