김유신
King Taejong Muyeol was born with the "sacred bone" rank of "seonggol". His father, Kim Yongsu (金龍樹), was a son of Silla's 25th ruler, King Jinji. When King Jinji was overthrown, all royalty from his line, including Kim Yongsu, were deemed unfit to rule over the kingdom. However, as Yongsu was one of the few remaining "seonggols", and married a "seonggol" princess (King Jinpyeong's daughter Princess Cheonmyeong), their child, Kim Chunchu, became "seonggol" and thus had a claim to the throne. Kim Yongsu was a powerful figure in the government; however, he lost all of his power to Kim Baekban, the brother of the king. In order to survive, he accepted to become a "jingol", the rank that was right below "seonggol", therefore removing the right of becoming the king for him and his son, Kim Chunchu. Following the death of his aunt, Queen Seondeok, Chunchu was passed over in favor of Jindeok of Silla, the last verifiable "seonggol". With her death, all the "seonggols" were dead, so somebody with the royal blood in the "jinggol" rank had to succeed the throne. Kim Alcheon (So Alcheon), who then held the title "Sangdaedeung", or highest post of government, of Silla was the original favorite to succeed the throne. His father was a "seonggol", who married a "jingol" woman so that his son would not be a "seonggol" and suffer from the fight for the throne. However, Kim Yushin supported Kim Chunchu, and Alcheon eventually refused the throne and supported Chunchu's claim. As a result, Kim Chunchu succeeded the throne as King Muyeol.