Before winter, taking into consideration the difficulty of crossing Han-gang during the cold season, the Japanese army, which advanced to Gyeonggi Province, retreated from Gyeongsang Province to the coastal area of Jeolla Province and tried to build a permanent camp by constructing a number of new castles on the outer border of the area of castles constructed during Bunroku war (ranging from Ulsan in the east to Suncheon-si in the west).
京畿道まで進出した日本軍は、冬の訪れを前にして寒冷期の漢江渡河の困難さを鑑み、慶尚道から全羅道の沿岸部へ撤収し、文禄の役の際に築かれた城郭群域の外縁部（東は蔚山から西は順天市に至る範囲）に新たな城郭群を築いて久留の計を目指した。