Dokdo was a territory of Usan-country in the 4th century. Usan-country was near Shilla, one of the three kingdoms that existed in Korean peninsula then. However, Isabu, the general of Shila, conquered Usan-country in 512. Therefore, Dokdo becomes a territory of Korea from that moment. Later on, in Goryeo dynasty and Chosun dynasty, Dokdo is still a territory of Korea. It can be proved by the books written in Goryeo and Chosun dynasty. King Sejong, the 4th king of Chosun, mentioned Dokdo in his book. He wrote that "there exists an island that could be was called as Usan-country during Shilla dynasty at the east of the country. It is now called as Ullengdo. Usan and Mulleung are not far from each other that they can be seen when the weather is good."
In 1900, the first Korean emperor, Gojong declared the "Imperial Decree No.41." It changed the name of Ulleungdo to Uldo and recognized Dokdo as Korean territory. The jurisdiction included both Ulleungdo and the two islands of Dokdo. "The location of the country office will be in Daeha-dong and the office's jurisdiction will span the whole of Ulleung, as well as Jukdo and Seokdo." Jukdo indicates an island two killometers off Ulleung in the east, and Seokdo is Dokdo.
After the Imperial Japanese era, by the end of the World War 2, Japan made the San Fransisco treaty to give up all the territories of their colonies, which included Dokdo. Japan admitted Dokdo as Korea's territory that in the first few years, Japan severely punished Japanese fishemen who illegally hunted and fished nearby or in Dokdo. However, suddenly Japan changed their status and is now claiming that Dokdo is their territory. The effort to recognize Dokdo as Korean territory is increasing everyday.