Kim Yu-sin was a Korean military general and politician in 7th-century Silla. He led the unification of the Korean Peninsula by Silla under the reign of King Muyeol and King Munmu. He is said to have been the great-grandchild of King Guhae of Geumgwan Gaya, the last ruler of the Geumgwan Gaya state. This would have given him a very high position in the Silla bone rank system, which governed the political and military status that a person could attain.

Silla, was a Korean kingdom that existed between 57 BCE – 935 CE and located on the southern and central parts of the Korean Peninsula. Silla, along with Baekje and Goguryeo, formed the Three Kingdoms of Korea. Silla had the lowest population of approximately 850,000 people, which was significantly smaller than those of Baekje and Goguryeo.