A.V. Williams Jackson attempts to uncover more about the religion of the Achaemenian Kings and the Zoroastrian religion. He does not expect to make all points clear connected with the Achaemenian faith, but he endeavors to bring together the material relating to the Achaemenian creed as fully as possible, and with a hope that perhaps some hints may be given with regard to the relation of the ancient Persian kings to Zoroastrianism. Williams Jackson does so by looking at information found in Old Persian inscriptions, such as Auramazda or the God of the Old Persian inscriptions, the Bagas or other gods besides Auramazda, Mithra and Anahita, Foy’s conjecture of Arstat, evil recognized as a principle in the Old Persian inscriptions, the commandment of Auramazda and the law, and religious observance and places of worship. He will also examine their religion according to non-Iranian inscriptions, classical allusions, allusions in the Pahlavi literature and Shah Namah, and other Oriental sources. All sources are needed to discover the truth, however Williams Jackson’s analysis did not produce many results.