The Romans ruled Illyria--which now became the province of Illyricum--for about six centuries. Under Roman rule Illyrian society underwent great change, especially in its outward, material aspect. Art and culture flourished, particularly in Apollonia, whose school of philosophy became celebrated in antiquity. To a great extent, though, the Illyrians resisted assimilation into Roman culture. Illyrian culture survived, along with the Illyrian tongue, though many Latin words entered the language and later became a part of the Albanian language. Christianity manifested itself in Illyria during Roman rule, about the middle of the 1st century AD. At first the new religion had to compete with Oriental cults--among them that of Mithra, Persian god of light--which had entered the land in the wake of Illyria's growing interaction with eastern regions of the empire. For a long time it also had to compete with gods worshiped by Illyrian pagans. The steady growth of the Christian community in Dyrrhachium (the Roman name for Epidamnus) led to the creation there of a bishopric in AD 58. Later, episcopal seats were established in Apollonia, Buthrotum (modern Butrint), and Scodra (modern Shkodr'). By the time the empire began to decline, the Illyrians, profiting from a long tradition of martial habits and skills, had acquired great influence in the Roman military hierarchy. Indeed, several of them went on from there to become emperors. From the mid-3rd to the mid-4th century AD the reins of the empire were almost continuously in the hands of emperors of Illyrian origin: Gaius Decius, Claudius Gothicus, Aurelian, Probus, Diocletian, and Constantine the Great.