Emperor Chongzhen patted Zhu Cilang on the shoulder and said, "If the Capital falls, I will disappear and leave behind a handwritten letter to announce to the world that it was a Jiannu spy who poisoned me. This way, you will have a legitimate reason to launch a campaign against the Jiannu."
Since ancient times, only wars waged with a just cause could win the mandate of Heaven and the support of the people.
When the Jiannu crossed the pass, Wu Sangui led the way, followed by the Eight Banners. They charged into Beijing under the banner of avenging Emperor Chongzhen, and the common people, unaware of the truth, opened the city gates to welcome them.
Chapter 19