Moon Embracing the Sun (2012)

Thirteen-year-old Heo Yeon U, the daughter of a high-ranking official, meets Crown Prince Yi Hwon at her brother's civil service exam celebration, and they fall in love. Yeon U is chosen as the Crown Princess, but the Dowager Queen orders her death to place Yun Bo Gyeong as the Crown Princess, securing more power. Yeon U is resurrected but loses her memories. Eight years later, she returns as a shaman named Wol while the king investigates her death, unaware that Wol is the woman he loves, all while facing political threats to his reign. (Source: MyDramaList) ~~ Adapted from the novel by Jung Eun Gwol.