[Ancient times] - Iseo-guk (country) and the Silla Dynasty
[The period of Three Hans] Iseo-guk is assumed to have sprung from Uyu-guk, one of the small tribal countries in current Cheongdo. Iseo-guk was a tribal country which covered most of the current area of Cheongdo with Baekgok-ri, Hwayang-eup at its center. Around the birth of Christ, as iron culture spread into the Korean Peninsular, small countries in the region were transformed into allied countries. Iseo-guk was one of those small countries in the Bronze Age and the early Iron Age. The prehistoric remains extensively distributed across the area of Cheongdo are from Iseo-guk from the day of initial human settlement to the time of its being integrated into the Silla Dynasty. In the 14th year of King Yurye of the Silla Dynasty (the year 297), Iseo-guk was reduced to Iseo-gun subject to the Silla Dynasty after being defeated in the last war with the Silla Dynasty at the Iseo Mountain Wall. The area of Cheongdo was a strategic key point when the Silla Dynasty tried to conquer the area neighboring the Nakdong River. Thus, after annexing Iseo-guk, the Silla Dynasty established a training field for Hwarang members around the area of Unmun, making it the foothold for unifying the Three Kingdoms. As a result, Cheongdo retains a lot of relics of military station which were used for the Silla Dynasty's westward advance as Cheongdo was a key military point rather than an administrative one.
The period of the Goryeo Dynasty
In 940, for the first time, three areas of Sosan-hyeon, Hyeongsan-hyeon, and Oak-hyeon were combined into the name of Cheongdo. In 983, Cheongdo was included in Gyeongju-mok (the capital at the time), and shortly thereafter, it was included in Yeongdong-do. In 1343, this area was renamed Cheongdo-gun, and in 1366 it was subjected to Miryang-gun.
The period of the Joseon Dynasty
In 1405, in the early Joseon Dynasty, Cheongdo-gun belonged to Gyeongsang-do, and in 1458 to Daegu-jin. Afterwards, this area had its name and administrative district changed several times due to frequent reformation in local administration. In 1896, as the system of thirteen national districts called Do was enforced, Cheongdo-gun came to belong to Gyeongsangbuk-do.
Modern times to the present
In 1919, Cheongdo-gun was reorganized into nine Myeons. In 1949 Cheongdo-myeon was promoted to Cheongdo-eup, and in 1979 Hwayang-myeon to Hwayang-eup. As a result, Cheongdo-gun came to include two Eups, seven Myeons and 212 Ris. The county office was originally located at Dongsang-ri, Hwayang-eup, and in 1916, was relocated to Gosu-ri, Cheongdo-eup. Since 1961, the county office has been located to Beomgok 2 ri, Hwayang-eup - Two Eups: Cheongdo-eup and Hwayang-eup - Seven Myeons: Gakbuk-myeon, Punggak-myeon, Iseo-myeon Gaknam-myeon, Maejeon-myeon, Geumcheon-myeon, and Unmun-myeon