Yuan Chonghuan
Since the time of Yuan Chonghuan, the Ming dynasty had rarely changed its Liaodong defensive strategy. Ming leaders largely spent their energies building fortresses, relying on artillery and cannons as defensive measures rather than going on the offensive. For a time this defensive strategy frustrated the Qing army, but eventually Hong Taiji was able to develop a solution for the Qing by reforming their logistical operations, creating supply lines that allowed them to prosecute long-term siege warfare.