Ahura Mazdā (also known as Ohrmazd, Ahuramazda, Hourmazd, Hormazd, Hurmuz, Aramazd and Azzandara) is the Avestan name for a divinity of the Old Iranian religion who was proclaimed the uncreated God by Zoroaster, the founder of Zoroastrianism. Ahura Mazda is described as the highest deity of worship in Zoroastrianism, along with being the first and most frequently invoked deity in the Yasna. The word Ahura means light and Mazda means wisdom. Thus Ahura Mazda is the lord of light and wisdom. Ahura Mazda is the creator and upholder of Arta (truth). Ahura Mazda is an omniscient (though not omnipotent) god, who would eventually destroy evil. Ahura Mazda's counterpart is Angra Mainyu, the "evil spirit" and the creator of evil who will be destroyed before frashokereti (the destruction of evil).
Ahura Mazda first appeared in the Achaemenid period (c. 550–330 BCE) under Darius I's Behistun Inscription. Until Artaxerxes II (405-04 to 359-58 BCE), Ahura Mazda was worshiped and invoked alone. With Artaxerxes II, Ahura Mazda was invoked in a triad, with Mithra and Apam Napat. In the Achaemenid period, there are no representations of Ahura Mazda other than the custom for every emperor to have an empty chariot drawn by white horses, to invite Ahura Mazda to accompany the Persian army on battles. Images of Ahura Mazda began in the Parthian period, but were stopped and replaced with stone carved figures in the Sassanid period.