<P> From at least the 6th century, when Silla acquired a detailed system of law and governance, social status and official advancement were dictated by the bone rank system . This rigid lineage - based system also dictated clothing, house size and the permitted range of marriage . </P> <P> Since its emergence as a centralized polity Silla society had been characterized by its strict aristocratic makeup . Silla had two royal classes: "sacred bone" (seonggol, 성골, 聖 骨) and "true bone" (jingol, 진골, 眞 骨). Up until the reign of King Muyeol this aristocracy had been divided into "sacred bone" and "true bone" aristocrats, with the former differentiated by their eligibility to attain the kingship . This duality had ended when Queen Jindeok, the last ruler from the "sacred bone" class, died in 654 . The numbers of "sacred bone" aristocrats had been decreasing for generations, as the title was only conferred to those whose parents were both "sacred bones", whereas children of a "sacred" and a "true bone" parent were considered as "true bones". There were also many ways for a "sacred bone" to be demoted to a "true bone", thus making the entire system even more likely to collapse eventually . </P> <P> The king (or queen) theoretically was an absolute monarch, but royal powers were somewhat constrained by a strong aristocracy . </P> <P> The "Hwabaek" (화백 - 和 白) served as royal council with decision - making authorities on some vital issues like succession to the throne or declarations of war . The Hwabaek was headed by a person (Sangdaedeung) chosen from the "sacred bone" rank . One of the key decisions of this royal council was the adoption of Buddhism as state religion . </P>

I am the king of silla in korean