For the details of Silla history, you can visit here.
Before Silla extended their political and cultural influences into the area, there were many small kingdoms, with a total autonomy. They Korean historians called them Jinhan Confederacy. They fought, and sometimes cooperated each other until the final unification
In the 1980's, archaeologists in Yeoungnam University Museum investigated royal tombs of Apdok-guk, one of the small countries. And they discovered many pieces of splendid cultural remains, showing even the kings of small regional sovereignty enjoyed all the comfort and convenience of living in a well established societies.
The remains collected from the tombs of Apdok kings were not limited to cultural ones. When the archaeologists opened the tombs, they discovered innumerable human and animal bones there. Considering that there were very few ancient skeletons maintained in the museum and institutes in Korea, this was the discovery very significant to related researchers. In 2012, some of archaeological scientists, including us, started to examine and made inventory of the bones. This project would be supported by National Research Foundation of Korea, for 3 years. As a biological anthropologist, we will do ancient DNA analysis for them, getting genetic profiles of the people buried in the tombs. This would be the one of the largest full-scale aDNA analyses performed on ancient Korean skeletons ever.