According to legend, three demi-gods emerged from Samsung-hyeol which is said to have been on the northern slopes of Mt. Halla and became the progenitors of the Jeju people who founded the Kingdom of Tamna.
It has also been claimed that three brothers including Ko-hu who were the 15th descendants of KoUlla, one of the Progenitors of the Jeju people, were received by the court of Silla at which time the name Tamna was officially recognized, while the official government posts of Seong-ju, Wang-ja and Do-nae were conferred by the count upon the three. While this was the golden period of Silla, the exact data is as yet unknown.
Although there is no concrete evidence of when the "Three Names" (Samseong-Ko, Yang and Pu) appeared nor for the exact date of when Ko-hu and his brothers were received by Silla. we may suppose that the founding Period by the "Three Names" occured during the Three Kingdoms (Goguryeo, Baekje and Silla) period on the peninsula.
Taejo, the foundoms (Goguryeo, Baekje and Silla) period on the same relationship to Goryeo as Tamna had been in its relation to Silla but with Tamna's refusal to accept this position the Goryeo court ordered a dispatch of army troops whereupon the chief of Tamna, Ko ja-gyeon, submitted to Goryeo and ordered his son. Prince Mallo, to Goryeo's court in 938. In 1105 (King Sukjong's 10th year), the Goryeo court abolished the name Takna which had to this time been used and from that year on, the island was known as "Tamna-gun" (district) and Goryeo officials were sent to handle the affairs of the island.
Tamna-gun was changed to Tamna-hyeon in 1153 during the reign of King Ui-jong and Choi Cheok-kyeong was posted as Tamna-Myeong or Chief of Tamna.
In 1121 during Huijong's reign, Tamna was renamed Jeju and the posts of Busa and Pangwan were established on the island.
In the 12th year of the reign of Wonjong, 1271, General Kim Tong-jeong escaped with what remained of his Sambyeolcho force from Jindo and built the Hangpaduseong (fortress) at Kwiil-chon from where they continued their fight against the combined Goryeo/Mongol army but within 2 years, faced by an enemy army of over 10,000 troops, the Sambyeolcho was annihilated.
The Yuan (Mongol) dynasty, in 1273 during the reign of Goryeo's King Wonjong, established a Daruhachi or military governor on the island and this was to last almost one hundred years with the island almost completely under the control of these governors.
After Yi Taejo established the Joseon (Yi) dynasty, all of the administrative rights and systems which Jeju island, had maintaining some independence until this time, were absorbed into the centralized from of government established by Joseon.
In 1402, in the 2nd year of the reign of King Taejong, the titles of Seongiu and Wangja which had so long been used on Jeju were abolished and to Seongju Ko bong-lyeo was given the symbolic title of Jwadojigwan and to Wangja Mun chung-se, the title of Seokdojigwan and in 1416, still in the reign of King Taejong, the island was divided into three major. Administrative districts : the area lying generally north of Mt. Halla was headed by a 'Moksa' or county magistrate while east in the area of Jeongui-hyeon (today;s Seongeup Folk village) and the south western area of Daejeong-hyeon (today's Moseulpo, Daejeong-eup and Mt. Sanbang) were headed by a Hyeon-gam (also county magistrate).
In August, 1864, both Jeongui and Daejeong hyeons were moved from the control of the 'moksa' north of the mountain in today's Jeju-si area and were renamed 'Gun" (county) and came under the direct control of the Gwanchalsa (governor) of Jeolla province but because of strife between these 'Guns' and the Jeju 'moksa', the system was abolished in January, 1880 and the two 'Gun' reverted again to 'hyeon'.
In 1895 (King Gojong's 32nd year), Jeju-mok was redesignated as Jeju-Bu with a governor (Gwanchalsa) and Vice-governor (Chamsagwan) and a police agency was newly established while in both Jeongui and Daejeong the offices of 'Gunsu', (county chief) were again established but the very next year, the office of 'Gunsu' was abolished and the old system was returned to.
Then, in 1906 abolishing the Moksa system altogether, the Gunsu or County chief system was adopted and in 1910, Jeongui and Daejeong were included in Jeju gun while Chuja-myeon was placed under the jurisdicion of Wando-gun, part of South Jeolla province.
Japan 'annexed' Korea in 1910 and in 1915 the gun or county system which had been adopted in 1906 was abolished and Jeju island was designated as part of the 'island' system and called Jeju myeon under South Jeolla province. In 1931, Jeju-myeon was raised to the status of Jeju-eup or 'township' which gave the island one township(today's Jeju-si area) and 12 'myeon'. On August 1, 1946, Jeju Special Self-Governing Province was removed from the 'island' system under South Jeolla province and designated as an independent province with 2 counties, North County and South County, one 'township', today's present Jeju-si area and 12 'myeon'.
The provincial adminstrative building was burned to the ground in September, 1948 (during the April 3rd Rebellion) and a new building was completed in 1-do, 2-dong in December, 1952. On September 1, 1955, Jeju Township was elevated to city status with 40 administrative wards which on January 1, 1962, were reduced to 14 wards.
On July 8, 1956, Seogwi, Daejeong and Hallim-myeons were raised to the status of townships while the southwestern portion of Hallim Township was separated and newly designated as the Hankyeong district(myeon) which gave the province one city, two counties, three townships and 10 myeon or districts with 14 wards in Jeju-si, May 23, 1979 saw the restructuring of the Jeju-si wards and the addition of three more, giving 17 wards.
In March, 1980, the construction of a new provincial office was started in Yeon-dong of Jeju-si and in December of that year the four myeon of Aewol, Gujwa, Namwon and Seongsan were elevated to the status of townships Giving the administrative area one city, two counties, seven townships, six districts and, within Jeju-si 17 wards.
In 1981, the development of the Jungmun Tourist Complex brought about the unification of Seogwi township and Jungmun-myeon (district) into one as Seogwipo-si consisting of 12 wards (dong) giving the province two cities, two counties, six townships, five districts and 29 wards.
On October 1, 1983, Jeju-si's Samdo ward was divided into two wards to give a total of 30 wards in the province.
Yongdam ward in Jeju-si was restructured into Yongdam ward one and Yongdam ward two on October 1, 1985 and Jocheon myeon (district) was elevated to the status of Township followed on April 1, 1986 with Yeonpyeong-ri Gujwa township being raising to the status of Udo district (myeon), the provincial area now administering 2 cities, 2 counties, 7 townships, 5 districts and 31 wards, the status of the province as of 3 December, 1996.
- Data : Jeju Statistical Yearbook 2005. Jeju Province.