Surnames reached several hundreds in number in the middle ages.

The common surnames include Kim, Ri, Pak, Jong, Choe, Yun, Ryu, Hong, Sin and Han. Two-letter surnames are Namgung, Tokgo, Sonu, Hwangbo, Puyo, Sagong, Sokmal and so on

Surnames indicate men's family lines and women keep their surname even after marriage.

With years going by, more and more surnames came into being, making it difficult to properly distinguish family lines.

Therefore, the surname origin began to be used among those same in surname but different in family line in the way of adding a locality name to a surname. Typical examples are Kimhae's Kim, Jonju's Ri and Milyang's Pak.

In the days of the Ri Dynasty, some families apotheosized famous scholars, politicians and generals of the same blood as their progenitors to distinguish themselves from others.

The surnames with many origins in the period are Kim, Ri, Choe and Pak.

It is a custom of the Korean people to refrain from marriage between those of the same surnames and origins to give birth to fine posterity.