Into Shangluo with eighteen riders
In 1638 Li Zicheng was ambushed and wiped out by Hong Chengchou and Sun Chuanting at the Southern Plain of Tong Pass, breaking out with only seventeen riders including Liu Zongmin and hiding in the Shangluo mountains. By any measure this force had been reduced to zero. But the Ming court’s surtaxes went on producing the displaced, and two years later a great famine struck Henan; he came out of the mountains and raised his arm, and "tens of thousands followed." The arithmetic of a peasant war is merciless: an army can be annihilated, but the despair that produces armies cannot.
Forty-two days
The Dashun army kept fair discipline on first entering the capital, but soon turned to "extorting funds to aid the army": torturing Ming officials and nobles, wringing out seventy million taels under torture. The watching gentry class swiftly turned about and staked their bets on the Qing beyond the passes. Wu Sangui had been ready to submit, but hearing his property confiscated and his beloved Chen Yuanyuan seized, "in a rage that stood his hair on end" he went over to the Qing. At the Battle of Yipianshi at Shanhaiguan, the Dashun army collapsed under the charge of the Qing cavalry. From entering the capital to abandoning it, forty-two days — winning the realm and holding the realm are two different crafts, and he had learned only the first.