All ancient kings of Iran tried to show their power is coming from Ahura Mazdā and Ahura Mazdā would convey this holy Aura through his helpers. One of this goddess is Apam Napāt. During time Goddess Apam Napāt's name changed to Ānāhītā but its power and role still was the same. With search at Avestān we can find Goddess Apam napāt as the first goddess in Avestān which is linked to water, also we can see how water is holy for Iranian. In ancient Iranians belief, Mehr as giving the Aura and Apam napāt and Ānāhītā as conservative of Aura are complementary each other. By research about the first source of Goddess Apam Napāt and Ānāhītā that had vital importance for transferring the great force Aura to ancient kings, and by trace footprint of ancient role of Apam Napāt we are able to find the signs, and confirm an important part of legitimacy by very powerful transporter of Aura to kings in many historical periods.