Kim is the most common surname in the Korean Peninsula, accounting for nearly 22% of the population

In South Korea, one in five people carry the surname Kim. Together with Park and Lee, the three surnames account for almost half of its entire population, but why is this the case?

Korea’s neighbouring Asian counterparts, China and Japan both have diversity amongst their common surnames – China has roughly 100 different surnames, whilst Japan has around 280,000 distinct family names.

Perhaps Korea’s lack of diversity in its family names is rooted in its history. Surnames were a rarity in Korea until the late Joseon dynasty (1392-1910). Surnames were a privilege of the royalty and aristocrats, whilst slaves and outcasts such as butchers, shamans, prostitutes, artisans, traders and monks did not have family names.

Surnames became more common as the local gentry grew in importance. Wan Geon, the founding king of the Goryeo dynasty (918-1392) rewarded loyalty amongst government officials with surnames. Furthermore, a civil service examination that granted social advancement required applicants to register a surname.

Elite households and the upper class thereby began registering family names. Successful merchants also began to take on surnames too by buying a genealogical book from the elite who became bankrupt or needed the extra cash. Once bought, the buyer would be able to take over the surname registered to the genealogical book.

Kim Jong-kook by se7en0704

Kim Jong-kook by se7en0704

Surnames thereby became a monetary asset, with non-relatives acquiring noble surnames as a form of repayment.

Family names such as Lee and Kim were commonly used by royalty in ancient Korea, making them the most desirable surnames.

To distinguish between the surnames, a number of clans were tagged onto the name. Kims have roughly 300 distinct regional origins, such as the Gyeongju Kim and Gimhae Kim clans.However, due to the small pool of names, nobody was sure who was a blood relation. To address this, the king in the late Joseon period enforced a ban on marriages between people with identical clans – a law that was removed in 1997.

Korea abolished its class-based system in 1984, which allowed those with a lower status to adopt a surname too. Commoners tended to adopt the surname of their master or just took a common one.

In 1909, Korea passed a law that required everyone to register a surname.

Nowadays, clan tags no longer bear the same relevance, but yet the number of new Park, Kim and Lee clans is growing. As foreign nationals become naturalised Korean citizens, they often settle on Kim, Lee, Park or Choi, according to government figures.

South Korea has a saying suggesting that if you were to throw a stone from the top of Mount Nasam (in the centre of Seoul), you are bound to hit a person with the surname Kim or Lee. This saying continues to ring true.