The kingdom of Tamna or Tamna guk ruled Jeju Island from ancient times until it was absorbed by the Korean Joseon Dynasty in 1404. This kingdom's also sometimes known as Tangna (탁라), Seomna (섭나), and Tammora (탐모라). All of these names mean "island country." There's no historical record of the founding or early history of Tamna. One legend tells that the three divine founders of the country—Ko (고), Yang (양), and Bu (부)… (More on Tamna)