A look into an interesting battle account

『順治十五年,有族兄旅寓鎮江，適海寇(明鄭)入犯鎮江，城中官軍悉出城拒賊。族兄與居民並派出登城守埤，因得縱觀戰事云。官軍出城，陣于江口，江中海寇巨艦抵岸，遙聞掌號聲。寇蟻附而上，集於沙洲， 約數千人，通為一圓陣。四面籐牌皆外向，若聚數千牌為一牌，兵隱不見。官軍馳馬往衝，將近百步，鞚馬引弓射之，矢不能入，寇屹然不動。官軍鳴金徐退。復鼓而進。乃前衝射。寇仍不動。如是者三，寇陣寂然。徐聞其陣中擂鼓甚急，約十數聲，寇一齊吶喊，分為五陣。官軍方愕而視之，其中陣復擂鼓，五陣齊吶喊分為二十五陣。其中陣復擂鼓，各陣吶喊， 分為無數陣。睇視之，則皆五人為伍也，散如亂星，飛奔而來。官軍射之不中，遽薄我陣，徑斫馬足，箭無可施；馬驚刀傷，望城回奔，寇隨以入，城遂陷。』

"In the fifteenth year of Shunzi (AD 1659), my clan brother travelled to Zhenjiang, and just happened upon the pirate (i.e. Koxinga) invasion of Zhenjiang, and all government troops in the city moved out to defend against the pirates . My clan brother was assigned to guard duty on top of the city wall along with the locals, so he was able to witness the battle. (He saw) the government troops move out of the city and deploy at the river mouth, and from the river the pirate's giant ships reach the shore. (My clan brother) heard the sound of horn from afar, and the pirates swarmed to the shoal. (The pirates) numbered several thousand, and formed into a round formation, rattan shields facing outwards in all directions. Thousands of shields gathered together like one shield, hiding all (pirate) troops behind. Government troops rode out and charged forward. When they approached a hundred bu (from the pirates), they pulled the reins and loosed the arrows. Yet the arrows did not penetrate (the shields), and the pirates did not budge in the slightest. Government troops sounded the gong and withdrew, then beat the drum and charged again. The pirates still did not move. The same scenario repeated thrice, and the pirate formation remained silent. (Suddenly) he heard about a dozen of rapid drum beats from the pirate formation, and the pirates let out a great shout and split into five formations, while government troops could only stare in astonishment. The centre formation drummed again, and the five formations shouted together and split into twenty-five formations. Centre formation drummed again, and the formations shouted again, then split into countless formations. (My clan brother) looked closely, and noticed that each formation consists of five troops. (They) scattered like fire sparks and sprinted forward. Government troops could not hit them, (and the pirates) seeped into our formation, dashing and slashing at the horse legs. (Our) arrows were useless, the horses spooked and injured by swords, (so the government troops) rushed back into the city. The pirates followed them in, and the city fell."

The account above was given by Hong Heng Qiu (洪横秋), an early Qing period poet, relaying witness account of his clan brother (a distant cousin) that saw the battle first-hand. In contrast to the vast majority of battle accounts in Chinese records, which tend to be sparse on details, Hong Heng Qiu's account offers us a glimpse into the battlefield of seventeenth century China, and provides us with invaluable details regarding how a battle unfolds, how southern troops armed with short weapons were able to resist cavalry charge, and the infamous infantry countercharging cavalry that I mentioned a few times elsewhere in my blog.

Analysis

A few observations can be made based on this battle account:

1. Chinese (in this case Manchu) cavalry charge was accompanied by a shower of arrows.

I mentioned this in passing in my blog post discussing cavalry tactics, and here the battle account describes the charge in more detail. An interesting detail is that Manchu cavalry stopped at a distance of around 100 bu (~ 163.5 metre/178.8 yards) to shoot their arrows — the usual distance where a typical cavalry charge changes from a trot into a gallop. No doubt Manchu cavalry would also charge home in gallop should their enemy show signs of disruption.

2. Heavy cavalry units could make no impression upon well-equipped and disciplined foot soldiers who kept their formation unbroken.

Theotokis's remark was just as applicable in China as it did in Civitate. However, it should be noted that Chinese records rarely discuss about utilising the shock and awe from a cavalry charge to cause infantry formation to waver or break. The underlying assumption was that the vast majority of foot soldiers were disciplined enough that expecting them to break immediately would be impractical. 

Instead, a common tactic used by Chinese cavalry to attack infantry formation that withstood multiple cavalry charges was to feint a failed cavalry charge to goad the infantry to break ranks and attack, then suddenly charge again without regrouping first.

3. Complex formation manoeuvring

The battle account gives me the impression that Koxinga's rattan shieldmen had more in common with a marching band show than Roman Testudo. The ability to split into multiple smaller formations almost instantaneously, while under direct threat of cavalry charge, was particularly impressive. I believe it was the emphasis on small unit tactics that make this kind of complex manoeuvring and formation changing at the intra-unit level possible.

4. Spread up to resist cavalry charge

Ordering troops to spread out to resist a cavalry charge may seem like it flies in the face of all conventional wisdoms, as the usual tactic for foot soldiers to resist cavalry charge was to form up into tight formation (preferably with long polearms sticking out in all directions) while maintaining order and morale.

Nevertheless, this tactic was based on an entirely different line of thinking — one that utilised the concept of saturation attack (or rather, saturation defence). Essentially, by abruptly splitting into many smaller units, the defending infantry presented so many targets for the cavalry to attack that they overwhelmed the cavalry's ability to respond effectively. As a result, the cavalry would either be surprised into inaction, or the charge became disrupted and disorganised (as each horseman randomly charges at a different target), losing much of its effectiveness. The infantry could then regroup and countercharge the now-disordered cavalry.

5. Sprinting countercharge

In order for Koxinga's foot soldiers to catch up with Manchu cavalry, they would have to traverse a distance of 100 bu before Manchu cavalry could react. This means they had to charge at sprinting speed, similar to the famous wild charge of the Scottish Highlanders but in a more controlled fashion.