Armenian mythology originated in ancient Indo-European traditions, specifically Proto-Armenian, and gradually incorporated Hurro-Urartian, Mesopotamian, Iranian, and Greek beliefs and deities. The pantheon of Armenian gods, initially worshipped by Proto-Armenians, inherited their essential elements from the religious beliefs and mythologies of the Proto-Indo-Europeans and peoples of the Armenian Highlands. Historians distinguish a significant body of Indo-European language words which were used in Armenian pagan rites. The oldest cults are believed to have worshipped a creator called Ar (or possibly Ara), embodied as the sun (Arev or Areg); the ancient Armenians called themselves "children of the sun". Also among the most ancient types of Indo-European-derived worship are the cults of eagles and lions, and of the sky. After the establishment of Iranian dominance in Armenia in the 1st millennium BCE, Zoroastrianism had a major influence on Armenian religion. Until the late Parthian period, the Armenian lands adhered to a syncretic form of Mazdaism, which mixed Iranian religious concepts with traditional Armenian beliefs. For example, the supreme god of the Armenian pantheon, Vanatur, was later replaced by Aramazd (the Parthian form of Ahura Mazda). However, the Armenian version of Aramazd preserved many native Armenian aspects. Similarly, the traditional Armenian goddess of fertility, Nar, was replaced by Anahit, which may derived from Persian Anahita, although the Armenian goddess was entirely distinct from her Iranian counterpart. In the Hellenistic age (3rd to 1st centuries BCE), ancient Armenian deities were identified with ancient Greek deities: Aramazd with Zeus, Anahit with Artemis, Vahagn with Heracles, Astłik with Aphrodite, Nane with Athena, Mihr with Hephaestus, Tir with Apollo. After the formal adoption of Christianity in the 4th century CE, ancient myths and beliefs transformed to adhere more closely to Christian beliefs. Biblical characters took over the functions of the archaic gods and spirits.