The story of two lovers unable to marry due to family opposition isn't unique to Shakespeare's 'Romeo and Juliet.' Until just a few decades ago, a unique and powerful law existed in Korea: a 'Gimhae Kim' could not marry another 'Gimhae Kim,' and a 'Jeonju Lee' could not marry another 'Jeonju Lee.' This was the **Dongseongdongbon Geumhon (同姓同本 禁婚)** system, the ban on marriage between individuals of the same surname and ancestral origin.
The Powerful Belief in 'One Root'
Dongseongdongbon (同姓同本) literally means 'same surname and same ancestral origin.' In traditional Korean Confucian society, if the ancestral origin (bon-gwan) was the same, everyone was considered a 'blood relative' (혈족, hyeoljok), or close kin, descended from a single ancestor. Even if they had split off tens or hundreds of hundreds of years ago and had never met, the perception that they were one family according to the jokbo (family register) was very strong.
Against this backdrop, the system, which began during the Joseon Dynasty, legally prohibited marriage between men and women with the same surname and ancestral origin under the pretext of preventing incest and maintaining family order. For example, a Gimhae Kim and a Gyeongju Kim could marry because their ancestral origins were different, but marriage between two Gimhae Kims was impossible.
The Conflict Between Law and Love, and the Change
As industrialization and urbanization progressed, this law began to cause serious social problems. People belonging to clans with large populations, such as the Gimhae Kim and Miryang Park clans, had great difficulty finding spouses. Tens of thousands of 'victims of the law' had to live in common-law marriages, unable to even register their children's births because they could not legally become husband and wife.
"In 1997, the Constitutional Court of Korea ruled that the ban on same-clan marriage was unconstitutional, infringing upon the people's right to pursue happiness and equality. This was a historic event where the traditional value of bloodline clashed with the modern values of individual freedom and dignity."
As a result of this historic decision, the ban on same-clan marriage was abolished.
The Current Law: No Marriage Within 8 Degrees of Relationship
After the ban on same-clan marriage disappeared, the Korean Civil Code established a new standard: a ban on marriage between **blood relatives within 8 degrees of relationship (8촌, chon)**. This is one of the broadest prohibitions on consanguineous marriage in the world.
- How to Calculate 'Chon': The relationship between a parent and child is 1 chon, and between siblings is 2 chon. First cousins are 4 chon, your parent's cousins are 6 chon, and the grandchildren of your grandparents' siblings are 8 chon.
Therefore, even if the surname and ancestral origin are the same, there is no legal problem with marrying if the degree of relationship is beyond 8 chon. For example, two people from the Gimhae Kim clan can marry if their relationship is 9 chon or more distant.
The history of the ban on same-clan marriage dramatically shows how traditional Korean perceptions of lineage and family have changed. Although the law has changed, the culture of asking for one's surname and ancestral origin remains in Korean society, continuing as a unique way of confirming identity.