Queen Sinseong[6] (Korean: 신성왕후 김씨; Hanja: 神成王后 金氏; 900–?)
or formally called as Queen Dowager Sinseong (신성왕태후; 神成王太后) was a Silla royal family member as the first cousin of King Gyeongsun[7] who became the fifth wife of Taejo of Goryeo[citation needed] and the mother of Anjong of Goryeo,[8] also the grandmother of Hyeonjong of Goryeo which she later posthumously honoured as queen in 1010 under his command.
In November 935, when King Gyeongsun expressed his intention to surrendered Silla to Goryeo, Taejo sent an envoy in return this request.
[9] Taejo also wanted to married with Silla's royal member and Gyeongsun said: After this, Gyeongsun sent his older first cousin, Lady Kim to Goryeo and become the 5th wife of Taejo.
[11] Queen Sinseong was the great-great-great-granddaughter of King Munseong and the daughter of Kim Eok-ryeom, who was the uncle of King Gyeongsun, making her King Gyeongsun's first cousin.