Three Kingdoms of Korea
The Samguk Sagi (History of the Three Kingdoms) and Samguk Yusa (Memorabilia of the Three Kingdoms) record that there was a country called Sabeolguk in Sangju. The geography book and biographies in the Samguk Sagi state that during the reign of Silla King Jeomhae (247~261), Sabeolguk, which then belonged to Silla, changed its policy and surrendered to Baekje. When the Sabeolguk king refused a Baekje envoy's proposal to make peace, Baekje sent general Seokuro to conquer the country. In 249 AD, Sabeolguk was supposedly annexed by Silla after being caught in the middle of the Baekje-Silla battle over territorial expansion. In the 1 st century BC, it is estimated that there was Goryeong Gaya in Hamchang.
In the territory of Sabeolguk, which was annexed to Silla during the reign of Silla King Jeomhae, Sabeolju ( 沙伐州 ) was established in the 12 th year of Beopheung (525) and had Yideung ( 伊登 ) as its governor. Silla divided local districts into 5 Jus ( 州 ) and named local governors Gunju. After that, the districts was integrated into Silla and became one.
* Current Status of the Establishment of 5 Jus ( 州 ) ① 上州 (Sangju), ② 下州 (Changyeong), ③ Hansanju (Gyeongju), ④ Siljikju (Samcheok), ⑤ Biraeholju (Anbyun)
In the 13 th year of Jiheung (552), 6 Jeongs ( 停 ), military organizations, were founded in 5 Jus, and one Gundan ( 軍團 : military camp) was established in Sangjujeong ( 尙州停 ).
In the second year of the reign of Queen Jindeok (648), General Kim Yu-shin was appointed as commander-in-chief of the march of Sangju, which served as a combat base and became a very significant area during the battles between Silla and Baekje
Some record states that troops led by Kim Yu-shin, Pumil, and Heumchun by order of King Taejong Muyeol (660) to conquer Baekje, stayed in the Geumdol Fortress ( 今突城 ) for 37 days and, upon the notice of surrender from Baekje's King Uija, departed for Soburi Fortress. (Geumdol Fortress is the oldest fortress reminiscent of the Silla Period - Historical Site of National Defense No. 30)
* Served as a combat base during the Baekje Conquest
In the 13 th year of the reign of King Munmu (673), Sangju-jeong was promoted and reorganized into Guidang ( 貴幢 ) and remained politically and militarily significant for a long time even after the unification of the three kingdoms.
Silla's military organization consisted of Jeong ( 停 ) and Dang ( 幢 ), which included military camps ( 軍營 ), army corps ( 軍團 ) and units ( 部隊 ) and Daedang ( 大幢 ) was placed near Gyeongju, the capital of Silla, and Guidang ( 貴幢 ) in the military zone (Gungwan-gu 軍管區 ) of a local area.