Seongdeok Daewang (reigned 702–737) was the thirty-third king of the ancient Korean kingdom of Silla. He was the second son of King Sinmun, and the younger brother of King Hyoso. In 704 Seongdeok married Lady Baeso (Queen Seongjeong), the daughter of Gim Wontae. In 715 their son, Junggyeong, was named Crown Prince and heir presumptive. Shortly thereafter, and for reasons unclear but quite likely having to do with a power struggle at court between the king and the clan of the queen, Queen Seongjeong was evicted from the palace in 716. As further evidence of a possible power struggle, the next year Junggyeong died under circumstances that remain unknown. Following the fall from favor of his first wife, King Seongdeog married Sodeok in 720, the daughter of the minister Gim Sun-won. Kings Hyoseong and Gyeongdeok were among the children of Seongdeok and Sodeok.

Seongdeok of Silla - Wikipedia