Late-Goryeo seongju of Tamna who helped bring the island back under Goryeo
| Era | 고려 후기 |
| Clan | 제주 고씨 |
Go In-dan (高仁旦) was a late-Goryeo seongju of Tamna; his dates are not recorded. According to an article citing the Tamna Inmulgo, when Kim Tong-jeong of the Sambyeolcho used Tamna as a base in the late reign of Wonjong, he and the prince Mun Chang-u reported the situation to the court, and a joint Goryeo-Yuan force put down the rebels.
After that, the Yuan set up a Tamna Command (chonggwanbu). The article says he became its chief in 1276, while the Encyclopedia of Korean Culture lists him as deputy of the command, so titles differ between sources. The command is said to have been changed to an anmusa system in 1284 and a jihwisa system in 1292.
In 1294 (20th year of Chungnyeol) Go In-dan and Mun Chang-u asked the Yuan court to return Tamna to Goryeo proper, and he is credited with helping bring the island fully back. He is said to have received a red leather belt, an ivory tablet and a hat from King Chungnyeol. He is honored as the founder of the Seongju-gong branch, whose line is said to have lived in Cheongju and Seoul. He shows how Tamna's autonomy was folded into Goryeo's county system.
After the rebels were crushed, the Yuan placed horse pastures and a command on Tamna. Under it he is said to have represented the islanders as chief or deputy of the command.
Tamna returned to Goryeo in 1294 at the request of Go In-dan and Mun Chang-u. The details of the petition should be checked against the original Goryeosa.
The Seongju-gong branch he founded lived in Cheongju and Seoul. Go Bong-rye of the same house later asked to revise the seongju title in early Joseon.
His tomb was not confirmed.
He is honored as founder of the Seongju-gong branch.