Defensive Reconstruction Plans during the Foundingof the Southern Song:Focusing on the Causing Worries around Belly and Back(腹背之顧) Strategy in the Lianghuai Region

The Southern Song court, deprived of much of the Northern Song’s military strength, was compelled to rebuild its forces to fend off the Jin’s elite forces from the north but struggled to mount sufficient resistance. Natural defensive lines proved futile in the face of the overwhelming military superiority of the Jin. the Southern Song adopted a delaying strategy aiming to deter their invasions while gradually restoring military capability. To ensure the success of this strategy, The grand garrison army (屯駐大軍) was positioned at the enemy’s front to block their penetration, while friendly forces would attack supply lines and cut off retreat routes from the enemy’s rear in the socalled causing worries around belly and back (腹背之顧) strategy. However, to bring an end to the war, it was essential encircling and annihilating the enemy. When the Jin invaded in 1140, the Southern Song applied the causing worries around belly and back (腹背之顧) strategy to intercept the Jin at the front and contain them from the rear, ultimately forcing the Jin to retreat after exhausting their ability to penetrate further. Pursuing the Jin, the Southern Song army successfully surrounded and annihilated Jin forces by coordinating frontal resistance from the central army with rear assaults by The grand garrison army. This enhanced military capacity enabled the Song to push through peace negotiations successfully.