It is believed that the Yuntanza Aji, Lord Gosamaru, built Zakimi Castle at the beginning of the 15th century and it was named Yuntanza Gusuku at the time. Before Zakimi Castle, Lord Gosamaru resided in Yamada Gusuku, located five kilometers to the northeast. Since the time of the Aji Haniji, the location of the Gusuku was to keep a sharp lookout on the Hokuzan Kingdom that attempted to build its might to rival the Chuzan Kingdom. However, in 1416 Gosamaru joined the forces fighting Hokuzan, which resulted in the subjugation of the Hokuzan Aji, Hananchi. After that, until 1422, Gosamaru assumed the duties of Hokuzan supervisor and lived in Nakijin Castle. Additionally, the history of Gosamaru's ancestral clan shows they were originally the lords of Nakijin Castle and were forced out with the rise of Haniji. Perhaps the retaking of Nakijin Castle fulfilled a long-cherished wish of Gosamaru to regain the land of his ancestors. Gosamaru subsequently built Zakimi Castle and moved there. To confront a renewed threat from an old enemy, Amawari of Katsuren, the Chuzan king ordered Gosamaru to move to Nakagusuku Castle from Zakimi Castle with its good harbor and enormous territory. After his move to Nakagusuku Castle, there is no confirmed historical documentation dealing with the positions of the other Aji chieftains toward Gosamaru. However, when Amawari attacked Nakagusuku Castle it is said the Yutanza Aji tended to support Gosamaru, commander of the troops. In another age, in the midst of the Battle of Okinawa, an anti-aircraft emplacement was constructed there to take advantage of its elevated position. It was also utilized as part of a U.S. military base after the war.